The High Court in Kenya on Thursday sentenced to death a senior policeman who killed a suspect by severely beating him whilst he was in custody, one of the harshest punishments over widespread police brutality in the East African country.

Such a conviction is extremely rare, despite the fact that human rights organisations have documented hundreds of cases of brutality and killings carried out by Kenyan police.

Activists have long accused Kenyan police of using excessive force with little risk of being charged or convicted. A police oversight authority set up in 2011 ended virtual police impunity and fostered prosecutions for abuses.

The officer, Nahashon Mutua, was in charge of a police station in the capital, Nairobi, when his victim, Martin Koome, was brought in following a domestic brawl.

The court heard that Mutua tortured the suspect and beat him repeatedly with a metal bar, leaving him bleeding badly with wounds on his head and fractured ribs.

The officer had earlier tried to frame an inmate for the murder.

Mutua has 14 days to appeal against the conviction.

Death sentences are not unusual in Kenya but they are generally commuted to life imprisonment. No executions have been carried out since 1987.