Kenyan police officers Naftali Chege (L) and John Pamba will face trial over the alleged killing f Alexander Monson, a British citizen who was found dead in his prison cell in 2012. Reuters

Four Kenyan policemen will stand trial for murder after a judge ruled on Monday they have a case to answer in the death of British aristocrat Alex Monson, 28, who died in their custody in 2012.

"The accused should tell the court what happened since the deceased was arrested in good health," High Court Judge Erick Ogolla ruled.

The policemen – Naftali Chege, Charles Wangombe Munyiri, Baraka Bulima and John Pamba – were accused of killing Monson, son of Nicholas, the 12th Baron Monson, and heir to a family estate in Lincolnshire in eastern England.

Monson was found dead in his cell after being arrested after police said he was in possession of cannabis.

The police have said he died of an overdose but his mother, Hilary Monson, told the court her son had never been a drug addict.

Two reports by government pathologists said he died after a traumatic blow to the head.

An inquest found there had been attempts to cover up the incident and threats against witnesses.

The ruling is the result of an inquest that began in 2019 in the coastal city of Mombasa, in a case seen as a test of whether Kenya’s security services could be held accountable for the use of excessive force and extrajudicial killings.

The judge said he was satisfied with the case presented by the prosecution, which sought to have the four face murder charges over Monson's death.

The judge said no evidence was presented in court to show he was assaulted elsewhere other than in the police station after he was detained.

Forty-five witnesses including police officers testified during the inquest.

"We are happy with this ruling and we hope at the end of day justice for my late son will be served," Ms Monson told Reuters after the ruling.

The trial of the policemen is due to begin on May 10. - The National