Money flows as fast as the champagne in the chic bars opening across Nairobi.
At the hand-carved bar in Sankara Hotel, listed as one of the world's coolest destinations by Conde Nast Traveller, bottles of Armand De Brignac cost $800 - a year's salary for the average Kenyan.
In the leafy suburbs, five-bedroom villas with servants' quarters sell easily for $1 million in cash, real estate agents say.
High-end residential property prices have shot up 37 percent since 2010 and the Nairobi market was a top performer in Africa last year, according to Knight Frank's Wealth Report.
Four-wheel drive Range Rovers are a must-have for the glamour set. Sales of the luxury Vogue model, with a starting price of $200,000, have quadrupled in the past two years, said John Odingi, senior salesman at CMC Motors in Nairobi.
The middle class is growing fast as the economy expands steadily and Kenya's government moves ahead with bold plans to turn Nairobi into an international financial centre by 2025 - part of its goal to pull East Africa's largest economy into the ranks of newly industrialised nations by 2030.
But there is a seamy side to all the glitz.
New data calculated for Thomson Reuters Foundation by Global Financial Integrity (GFI), a Washington-based financial watchdog, show the amount of illicit money entering Kenya from faulty trade invoicing, crime, corruption and shady business activities has increased more than five-fold in a decade to equal roughly 8 percent of Kenya's economy - and in recent years the pace of dirty money inflows has been accelerating.
Development groups and international policymakers are particularly concerned about this trend because the Kenyan government - despite long-standing problems with money laundering, drugs, corruption and terrorism in bordering states - is moving ahead with plans to strike a deal with the City of London to build Nairobi into a major international financial hub.
"There is nothing wrong with that goal, but you have to understand that there is a high price of entry," said Daniel Glaser, Assistant U.S. Treasury Secretary for terrorist financing.
"One of the prices of entry is having a well-functioning anti-money laundering and counter-terrorist financing regulatory and legal regime. They have not had this in the past, and they are in a dangerous neighbourhood," he said.
Already Nairobi is a regional banking centre. Adding a tax-free zone and financial trading desks would make it attractive as a capital-raising centre for business in the region and worldwide.
But doing so when global financial policymakers already have flagged Kenya for laxity on the money laundering front and it has shaky legal and regulatory foundations would risk deepening already serious problems, said Alex Cobham, a research fellow on illicit finance at the Center for Global Development.
"Typically, countries that have gone down this path have ended up bending much of their legislation to service a relatively small sector of the economy, and a smaller section yet of the population - so it's no surprise that we often see very serious governance and inequality problems in the typical 'tax haven' jurisdictions," said Cobham.
"In this case, you'd be mapping that onto a situation in Kenya where there are very serious concerns already about governance and growing risks related to inequality," he added.
Put simply, Kenya could turn itself into a major money laundering centre.
Kenya borders politically unstable Somalia and South Sudan to its north. Problems spill over from violence in the Democratic Republic of Congo to its west; proceeds from piracy in the Arabian Sea enter Kenya; al Qaeda branches operate in Somalia, using it as a base for attacks on Kenya and Uganda; and international drug traffickers from Asia and wildlife traffickers throughout sub-Saharan Africa use Kenya as a transit point, according to reports from the United Nations, the global regulatory group the Financial Action Task Force and the U.S. State Department.
Financial regulators are sufficiently concerned about illicit flows in the region that the East African Association of Anti-Corruption Authorities has asked the World Bank Institute to study how money from crime and corruption washes through Kenya.
Its preliminary findings, obtained by Thomson Reuters Foundation, painted a picture of a thriving underworld aided by political corruption and a large informal money transfer sector, known as hawalas, that regulations barely touch.
Bankers and business people told researchers that bulk cash was a common way to move illicit money across Kenya's porous borders and they describe a permissive culture where anti-money laundering laws are frequently ignored.
"Lack of resources contribute to this, but exacerbating Kenya's performance in curbing financial and trafficking crimes are the corruption levels in the country," it said.
A separate study in 2012 showed how easy it is to launder money in Kenya using untraceable shell companies, which are widely used to move dirty money internationally.
Out of 182 countries tested, researchers at the University of Texas, Griffith University and Brigham Young University found that Kenya - in violation of international rules - was least likely to ask people for identity documents when they tried to open a shell company.
Many longstanding factors help explain why Nairobi is an alluring place for illicit funds. Even shady money needs a safe place to reside, and Kenya's sophisticated financial services, business and legal sectors and relative political stability make it a safe house in a bad neighbourhood.
Decades of civil war have led to a massive inflow of refugees to Kenya from Somalia and the Sudans.
Wealthier families also see Kenya as a safe haven for their money, buying prime property and sending their children to top private schools.
The Somali diaspora has come under international scrutiny for its use of hawalas, which provide an easy route for criminal money because they are not tracked by governments.
The U.S. State Department has estimated that the Somali diaspora alone transfers millions of dollars every day from Europe to relatives in Nairobi's Somali-dominated Eastleigh, dubbed Little Mogadishu.
Estate agents suspect some of the surge in property prices is from sales to Somali maritime pirates.
But a recent study by the World Bank and U.N. Office of Drugs and Crime (UNODC) found no such evidence and that the sums involved are too small to be significant.
In 2011, Somali piracy was worth $150 million, the study said, but successful hijackings have declined thanks to tougher security aboard ships and increased Western naval patrols.
Kenya's weak criminal justice system and lax border controls also have allowed international drug trafficking to thrive, turning the country into a major transit point for heroin from Afghanistan, Pakistan and other parts of Asia, and cocaine from Latin America headed for Europe and North America, according to the UNODC.
Inside Kenya, politics and grand corruption have gone hand in hand for many years.
Government officials looted at least $1 billion from the central bank for bogus gold and diamond exports prior to the 1992 election.
A decade later, the Anglo-Leasing scandal exposed hundreds of millions of dollars stolen when inflated government contracts were awarded to fictitious firms to deliver services ranging from forgery-proof passports to naval ships and forensic laboratories - which never materialised.
In 2006, Charterhouse Bank was closed after a $1.5 billion money laundering and tax evasion scam.
The bank had close ties to Kenya's largest supermarket chain, Nakumatt, part-owned by a leading politician, John Harun Mwau, according to a Kenyan investigation.
The U.S government has named Mwau, an assistant minister in the last government, as one of the world's top drug kingpins.
Kenyan anti-corruption activists say the problem has become deeply embedded throughout the political class as a culture of impunity has taken hold.
"Once you have corruption at the top and it seems to get accepted, even the most corrupt people get elected, get appointed to positions of authority and it spreads down very quickly.
And it becomes much more difficult to deal with," said John Githongo, who worked under former President Mwai Kibaki but fled the country in 2005 in fear for his life when he unearthed the Anglo-Leasing scandal touching top ministers.
Kenya scores 27 on Transparency International's latest Corruption Perceptions Index out of a possible score of 100, putting it in 136th place out of 177 countries, on a par with Bangladesh, Ivory Coast and Guyana.
LIGHT TOUCH, DIRTY MONEY
Despite these problems, Kenya applies a light regulatory touch to its banking, finance and legal sectors.
It is a signatory of all the major international anti-corruption conventions and in 2009 passed a comprehensive law called the Proceeds of Crime and Anti-Money Laundering Act to crack down on financial wrongdoing.
Yet it has barely applied the law. Kenya waited three years before appointing an interim head to lead its new Financial Reporting Centre (FRC), which is responsible for issuing anti-money laundering regulations in line with global standards and to conduct investigations.
In its March report, the U.S. State Department said that banks file reports on suspicious money transactions only sporadically and most banks ignore rules on reporting currency transfers over $10,000. The government has no prosecutions under way for financial crimes.
The Financial Action Task Force, the official global watchdog, decided in October to keep Kenya on its "grey list" of countries it considers high risk for money laundering and terrorist finance activities.
However, Kenyan government officials said they are working hard to prevent dirty money crossing their borders.
"Money laundering can destabilise the financial sector so we have taken systematic actions to prevent it," Kenya's Treasury Secretary Henry Rotich said.
"We are members of a coalition of countries fighting money laundering on a global scale, so it is mischievous to refer to Kenya as a haven."
Jackson Kitili, interim director of the FRC, said he has an annual budget of $2.4 million and plans to more than double the intelligence unit's staff to 26 members from 12.
The centre has received 73 reports from financial institutions of suspicious transactions so far, 14 of which have been forwarded to the police for further investigation, he said.
He expressed confidence that Kenya can adequately regulate an international financial centre: "In short, having an institution like this one is enough to say that we are prepared to handle that," Kitili said.
There is no precise way to measure how much illicit money flows though any economy since its purpose is to evade detection, so global policymakers and academics rely on a range of indicators from government data to crime reports and anecdotal information.
Global Financial Integrity (GFI) uses government trade and balance of payments data to estimate illicit finance, and experts say its method provides a useful indication of the scale of the problem.
In Kenya's case, GFI found that in the decade ended 2011, $16.2 billion flowed into Kenya through trade mispricing and hot money that was not officially counted in its balance of payments reports - a more than five-fold increase over the period.
These illicit inflows peaked at $3.2 billion in 2010. In 2011, the latest period for which data is available, they stood at $2.7 billion for the year.
Kenya is far from alone when it comes to large inflows of dirty money and a lax regulatory environment. Nigeria, Liberia, Zambia and Ghana are among the other Africa countries that GFI calculates have large illicit inflows.
What makes Kenya stand apart, however, is its importance as a regional banking centre, its talks with the City of London to grow its footprint as an international financial centre and its strategic location in a dangerous neighborhood, GFI and other financial experts said.
By no means is its growing wealth all suspect. Africa has prospered greatly from the boom in commodities, riding China's rise as a global manufacturing powerhouse.
It is developing its own industries and service sectors, and as education, healthcare and governance have improved, wealth has spread through an expanding urban middle class, McKinsey Global Institute said in a recent study.
It estimates that African consumers, keen to enjoy the good life and buy new homes, will have more than $1 trillion in spending power this year.
Kenya is no different. One in five of its citizens today lives in a city, has some tertiary education and draws a salary.
Moreover, job opportunities are expanding as improved tax collection is swelling government coffers, and Kenya is spending big on infrastructure projects, a trend likely to continue as it starts exploiting offshore oil and gas discoveries.
Tax revenues have risen from 229 billion Kenyan shillings ($2.6 billion) in 2003/04 to 800 billion shillings ($9.2 billion) in 2012/13.
In this fiscal year, the government plans to spend a record 1.6 trillion shillings ($18.4 billion) to fund an expanded government and development projects.
However, anti-corruption experts say this economic vibrancy cannot entirely explain the property boom, fast cars and flashy cash in Nairobi, which sit incongruously alongside the grinding poverty of the majority of the city's population.
Millions of Kenyans live in overcrowded slums with reeking open sewers, earning barely enough money from odd jobs to eat one meal a day.
The boom in public spending has offered more opportunities for public graft, but more worrying, experts say, is a toxic brew that is developing of more criminal money entering Kenya - from drug cartels linked to organised crime, ivory poaching, arms trade and human trafficking - mixing in a political culture that accepts high levels of corruption, as long as it gets its slice.
These problems could deepen if Kenya moves ahead with building an international financial centre before it has a functioning system in place to stop money laundering, whereby regulators can check bank records and currency sales carefully, investigate suspicious activities and bring prosecutions.
"The Kenyans need to approach these risks with a seriousness of purpose and understand that given all the risk factors that they face, they really need a state-of-the-art system, especially if their goal is to be attractive to money coming in from around the world," said the U.S. Treasury's Glaser.
Samuel Kimeu, executive director of Transparency International Kenya, fears that criminal cartels already have gained such a hold on corrupt politicians that they risk turning Kenya into a vassal state.
"If illicit money is used to capture state power, then there has to be returns from that investment, and that return would be more impunity for those involved in these kinds of crimes," he said.
"You can actually end up losing a country."