My slow paced stroll at the Gaborone bus rank, which is always a bustle, is greeted by a quick motion of the hands by one of the white-clad women as she rubs two fingers of her left hand together. A double take and she confirms my suspicions with a question of whether I need to change any foreign currency.

An encouraging smile and she is at my side. Two other similarly-clad women who were also trying to draw my attention respectively step aside and focus on another passersby hoping they can rope in other prospective clients.

This is the capital city's bus rank indeed, where the Mazezuru women are a familiar sight and have virtually become part of the environment evidenced by their daily presence.Displayed for all to see are their wares of the day, sweets and juice cards for anyone who wants to top-up their air time.

Not so apparent is their more serious business albeit unlawful. It is a lucrative foreign-exchange business among this tightly knit group that works together as a family, never mind the fact that they will be going their separate ways come nightfall.

Penetrating the group to get information is no mean task and the friendly woman of only a moment ago immediately puts up a guarded look as soon as I tentatively request an interview. "No," she says firmly. Silence, then she elaborates, "I cannot tell you the details of that side of our business, it is unlawful and exposing ourselves to people like you will only make us vulnerable to the police who are eager to throw us into jail. What I can only tell you is that it is our livelihood and we raise our children through this trade. We also assist people who do not want to contend with the bureaucracy at the banks," she finishes.

Sensing that the woman will tell her friends that there is someone asking questions I move to the other side of the rank where another woman of the same cloth, boldly asks if I want to change any hard currency.

After telling her that I would like to discuss and negotiate the rate, she wants to know if it is a lot of money. When I give her an affirmative gesture, she tells me to wait for her just off the bus rank. Feeling encouraged because she has given me her cell number I patiently stand vigil while battling the scorching sun which is threatening to melt my ice cream cone which I am licking in as acceptable a speed as I can.

Forty minutes to the dot and my patience pays off. Martha, the Muzezuru woman, emerges from a dark van where I just manage to catch a glimpse of another white-woman. Could she be the woman with the money-bag I muse to myself?

Getting straight into business Martha tells me in simple terms that for every $US100, I will get P640. For every R100 I will get P90 and for every 100 pounds I will get P800. A quick check with one of the local banks earlier on had revealed that they were offering something slightly lower. I negotiate for something better and she agrees to give me an extra five Pula for every P1,000 as I have told her that I may change more than US$4000.

Do you deal with transactions of US$20 000? I ask her tentatively. "Of course, we will just agree on the rate and cash you instantly. Even if you want to change pounds we can help you," she says. I decide to come clean and tell her that I am writing a story about this particular line of business they are involved in. Surprisingly she is not fazed and agrees to tell me more although she warns me to be fast as another customer is waiting for her elsewhere.

To the occasional interruptions of her ringing phone, she tells me that the Mazezuru are a proud people who are raising their families as best as they can while at the same time providing people with an essential service.

"We are able to provide for our children no matter what the state of the economy is like primarily because we are raised from a very young age to be entrepreneurs. Foreign exchange dealing is not a high paying job as many people think, in fact we get profits of only P20 for every P1000" she says.

Probably in answer to my look of skepticism Martha adds, "Well of course the more capital you inject into the business the more profit you are likely to get." What about the risk factor I ask? The police for instance? She shrugs, "Well the police are a problem to us because when we are caught we are fined P1,000 and our money is confiscated, but we have learnt to avoid them as much as possible and are usually able to spot them when they make their patrols, even if they are in plainclothes."

The waiting van honks loudly as I scribble furiously. Mercy assuredly waves a hand to her colleague while warning me that her partner would not be amused if she knew what we were talking about.

She laments the scarcity of the Rand, a shortage she attributes to Zimbabwe, which is now using that currency as well as the US dollar officially. "Our customers are the local Batswanas, Zimbabweans, Nigerians and even Zambians and those who are buying the foreign currency are more than those who are selling it," says Martha.

She adds: "In our transactions we do not ask for identity papers and we do not charge VAT or commission that is why people are shying away from the banks and coming to us.

During the time when there were shortages of the Zimbabwe dollar we would travel to that country's border to deal and we were able to provide it to people who needed it. "She explains that there is a mutual agreement among families of the Mazezurus for the women to deal in foreign exchange while their men folk focus on welding, building, as well as selling cars. "We share the money as a family but our role as women is very important, as you know you cannot get money from welding and wardrobes every day, but for us the women we have liquid all the time because of the foreign exchange, and are able to buy food as well as clothes when we want to," she says.

"Listen I have to go," she says, and it is only then that I notice that the dark van had drawn up alongside us. Pushing my notebook in my handbag, I wave a hasty goodbye.Lettie Paulo, a Motswana who regularly 'buys' Rands from the Mazezuru had this to say, " They provide a good service and are available at all sorts of hours, besides the rate is always better as there are no hidden charges, and with the way things have become expensive, I can make use of every thebe."

Commenting on the risk of being defrauded Jonathan, a Zimbabwean says, "They are very honest people and more often than not I only count my money when I get home and it is never short, we must understand that these people run a business and it would be folly for them to cheat their customers who are usually regulars."

For Edward, another Zimbabwean, the whole transaction makes him uncomfortable because he is always keenly aware that the police could nab them, but feels he has no other choice. "For me it is not about the better rate as I would prefer to do things lawfully. My passport expired and I am waiting for a new one, as it is the only identification document the banks accept from foreigners I am left with no other choice especially now that my country has dollarised the economy," he explains.

Onkarabile Mogamise of Stanbic Investments is however convinced that people should follow proper channels of transactions, which are transparent.

"The economy of a country is a regulated, controlled and sensitive system and once money starts getting into the system through this illegal method of buying and selling, its value will eventually be affected. There is also the danger of counterfeit money eventually finding its way into the system in this manner," she says.