Mr Barua said the officers had travelled from Nairobi to Eldoret to arrest a suspect, Daniel Mairura, 32, claiming he had had obtained money by false pretences on Friday.

The officers, he said, were in the company of three other civilians; all residents of Nairobi.

"The officers currently in custody had travelled from Nairobi to arrest a suspect who is alleged to have been involved in a fraud case before being implicated in the bribe allegation," said Barua.

After arriving in Eldoret, Barua said the officers arrested Mr Mairura and together, they boarded a vehicle to Nairobi where the case was scheduled for investigations.

However, while on transit to Nairobi, he said the two directed the suspect to give them Sh600,000 bribe to free him.

The suspect is said to have informed his mother about the demand who in response said she had deposited the money in his Kenya Commercial Bank (KCB) account and that they could withdraw the cash while in Nakuru town.

"The officers are said to have demanded Sh600,000 in order to release the suspect. The suspect's mother tricked the officers she had deposited some cash in the suspects' account and alerted our officers" said Barua.