Three top Kenyan policemen have been suspended over the case of a man who allegedly pretended to be an assistant police commissioner for five years.

Kenyan Police Service Commission chief Johnstone Kavuldi said the officers had been adversely mentioned during initial investigations.

Last week, Joshua Waiganjo was charged with impersonating a police officer in Kenya's Rift Valley province.

He denied the allegation during a court appearance.

He was reportedly uncovered after flying on a police helicopter to investigate the November killing of at least 42 officers in the Suguta valley - the most deadly attack on police in the East African nation's history.

Kenya's President Mwai Kibaki ordered an investigation into Mr Waijano's case.

Mr Kavuldi said Rift Valley police boss John M'Mbijiwe, Anti Stock Theft Unit commandant Remi Ngugi and Njoro Officer Commanding Police Division Peter Nthiga have been sent home, Kenya's privately owned Daily Nation newspaper reports.

He said their continued stay in office would interfere with investigations, but he maintained that the officers were innocent, the newspaper reports.

Mr Waiganjo is said to have sacked and recruited several officers in Rift Valley province while allegedly impersonating the local police chief.

In court last week, he denied two counts of impersonating a police officer, one of illegal possession of police uniforms and one of robbery with violence.

The case was adjourned to allow Mr Waiganjo to seek medical treatment for diabetes, local media reported.