Kenya MP Moses Kuria has told the BBC he received a $1,000 (£700) bribe in parliament last year to back the appointment of the majority leader.
“It is not unusual for members to get this kind of an inducement,” he said, adding he would return the payment.
Mr Kuria made the remarks as he and two other colleagues are to be censured for alleging pay-outs were made to back a recent constitutional amendment bill.
Majority leader Amos Kimunya has denied that bribes are paid in parliament.
The BBC has asked Mr Kimunya to respond to Mr Kuria’s specific allegation but has not yet had a response.
Kenyan MPs are some of the best paid lawmakers in the world – and officials estimate the East African nation loses billions of dollars every year to corruption.
Mr Kuria said he had witnessed corruption many times in parliament.
“And it has happened countless times for the eight years that I’ve been in parliament,” he told BBC’s Newsday programme.
“Obviously these things don’t happen on camera.”
He gave the appointment of Mr Kimunya as an example. He replaced Aden Duale as majority leader in the national assembly last June.
The MP for the Gatundu South constituency admitted that the corrupt practices were wrong.
“It is wrong. And I think yes… given an opportunity I would refund at least the one I can most vividly recall,” he said.
“I’ll probably do [it] today… refund the $1,000 that I did receive to vote in Amos Kimunya as the leader of the majority.”
Mr Kuria gave the BBC an interview as he has been summoned to appear before the house speaker for alleging some politicians received about $1,000 to vote for the constitutional amendment bill known as the Building Bridges Initiative (BBI).
The aim of the bill – backed by the president and leader of the opposition Raila Odinga – is to address the main challenges the country has faced since independence such as ethnic antagonism, corruption and devolution.
But critics say it will only increase waste as it will increase the number of parliamentary seats and bring back the post of prime minister and several deputies.
Mr Kuria is a supporter of Deputy President William Ruto, who does not back the BBI bill, and is a bitter rival of Mr Odinga, with the two men manoeuvring to succeed Mr Kenyatta as president in elections due next year.
Despite some initial opposition the BBI bill has been passed by county assemblies and recently by parliament.
Mr Kuria told the BBC other inducements had been used to persuade politicians – like the demand by county assembly members that they would only back the BBI bill for car grants, roughly worth $20,000 each.
The Salaries and Remuneration Commission (SRC) approved the grants in February.
However, Kenya’s High Court on Thursday ruled that the bill was unconstitutional, scuppering plans for it to be put to a referendum later this year.