Police in Nairobi are investigating circumstances under which community mobiliser and politician Billian Okoth Ojiwa went missing without a trace on Sunday.
Mr Ojiwa, who is in his early 30s, is best known for the Ficha Uchi Initiative, a programme he founded that gives school uniforms to needy children.
He is also the chairman of the youth congress of the Kenya African National Union (Kanu).
His wife Nerima Wako, the CEO of Siasa Place and a columnist with The EastAfrican, told the Nation that she was with him at her parent's house on Sunday when he stepped out at around noon.
Mrs Ojiwa said he walked out without carrying most of his possessions.
"He didn't have his phone, his car keys or his office keys. I thought he had gone to the shop. I haven't seen him since then," she said.
Mrs Ojiwa said she had filed a report at Kilimani Police Station on Monday and was told to return on Tuesday morning.
"He's been missing since Sunday at noon; so, it's been more than 24 hours without any contact whatsoever," she said, noting that she will be more comfortable to share more details around the disappearance after talking with the officer handling the matter.
Mr Ojiwa's disappearance was a trending topic on Twitter on Tuesday morning, with concerned Kenyans sharing the news of his disappearance through #FindBillianOjiwa.
"I hope Billian is safe even as the search for #FindCarolineMwatha continues," tweeted Phelix.
"Dear God, please protect him and watch over him. Please be with him and keep him from harm," typed Ronoh.
Mr Ojiwa is most known in Mathare, a slum area that nurtured him after completing his high school education.
He told Nation in 2017 that he was orphaned at 14 and grew up in poverty, and his star started shining when he moved to Mathare to help his aunt run a restaurant.
It is in Mathare that he started the Billian Music Family, an initiative that helps children record and market their music.
He started the Ficha Uchi Initiative after a parent asked him to help buy uniform for her daughter in 2013.
"When I visited her daughter's school, I realised that many other pupils there could not afford uniform. This was the inspiration behind the 'Ficha Uchi' campaign," he said.
In the 2013 General Election, Mr Ojiwa was one of the nine aspirants gunning to be Mathare MP, a race that was finally won by ODM's Steven Kariuki after a by-election in 2014.
Mr Ojiwa's disappearance caused more concern among Kenyans because another mobiliser has been missing since Thursday.
Ms Caroline Mwatha Othieng, who worked with the Dandora Community Justice Centre, took her daughter to school last Thursday and has not been seen since.
The organisation's coordinator Wilfred Olal told NTV on Monday that they did not know of any direct threats on Caroline's person but that the group had been at crosshairs with the police over extra-judicial killings.
"Carol was a key monitor on human rights violations, especially police killings and police brutality cases," Mr Olal said.
On Monday evening, human rights group held a vigil at the Dandora Community Social Justice Centre in solidarity with her.