Former Marlborough schoolboy Alexander Monson, 28, was taken ill hours after he was detained in the coastal town of Diani.
Alexander, who was the son of the 12th Baron of Monson, Nicholas Monson, died soon after he was taken to hospital for treatment, according to local police.
The cause of death is not yet determined, but a spokesman for the family said: “Alexander had previously enjoyed robust good health which makes this all the more shocking. The cause appears to be heart or respiratory-related, but it is too early to say any more.”
But a close friend claimed his death was caused by “police brutality”.
The friend said: “He was a great guy and I would love to see those bastards go to jail for what they have done.
“His death was a result of a combination of things. I wouldn’t say it was murder, but it was definitely a case of neglect. He was being held in custody and was not given the medical assistance he needed. It wasn’t a pre-existing medical condition, it was something else that started it. Perhaps a certain amount of police brutality.”
Monson, who went to Marlborough College in Wiltshire at the same time as Pippa Middleton, had lived and worked in Kenya for two years in meat processing and bamboo cultivation.
A family friend said: “Alexander was a witty, charming and sincere chap. He had a degree in psychology and also studied at Chelsea Art College, where he had won a scholarship. His was a life of such enormous promise.”
Lord Monson, 56, is the great nephew of writer Dylan Thomas.
