By David Bamford
BBC News Africa analyst
Kenyan MPs who interviewed the exiled former anti-corruption investigator said they were "astounded" by evidence of alleged government corruption.
Mr Githongo says ministers have blocked his investigations
John Githongo - who gave his testimony in London - has directly implicated several Kenyan government ministers in an alleged multi-million dollar scam.
The head of the delegation said Mr Githongo's information would be acted upon following a report to parliament.
Last year, the whistle-blower fled to the UK after he received death threats.
Kenya's Parliamentary Public Accounts Committee does not normally move outside the confines of the National Assembly building in downtown Nairobi.
But this weekend, senior members led by committee chairman, Uhuru Kenyatta, flew to the Kenyan High Commission in London.
They wanted to hear and see for themselves John Githongo's testimony and evidence of corruption in the Kenyan government.
Mr Githongo said he could not give his testimony in Kenya because of death threats.
'Amazed and astounded'
Mr Kenyatta said they have been shocked at what Mr Githongo had told them.
"Without a doubt, some of us are actually amazed and astounded by the extent of information that he has.
"Ultimately, everything that we have heard, all the evidence that we have gathered, all the material that we have collected will be made available to our parliament, to the people of Kenya and to the world as soon as this report is completed," he said.
The scandal may undermine President Kibaki's administration
Mr Kenyatta said John Githongo was thorough, convincing and willingly gave his testimony under oath.
At the heart of the allegations are claims that government ministers colluded in deals worth hundreds of millions of dollars with companies that either did not exist or massively inflated their prices.
And Mr Githongo has started naming names.
As a result, Kenya's finance minister has resigned, and the energy minister and vice president are having to fend off calls for them to resign too.
It is not clear how far this process will go or whether it will eventually undermine President Mwai Kibaki's administration altogether.