A convicted killer died in a jet ski crash on the first day of a family Christmas holiday in the Caribbean, an inquest heard.

Jordan Mayers, 29, was jailed in 2007 over the killing of Emmanuel Odenewu, 19, who was stabbed in the head, neck and chest at a bus stop outside Lewisham Police Station in a row over drugs.

An inquest heard Mayers had been released from prison and was turning his life around with a university course in business management when he died in the freak accident in December 2016. He crashed into his cousin’s jet ski off a popular tourist beach in Barbados and suffered a fatal head injury, Southwark coroner’s court was told. However, the full circumstances of the death, in rainy conditions on a beach without lifeguards, might never be known due to flaws in the local police investigation.

Mayers, from Lewisham, was originally found guilty of murdering Mr Odenewu, a Kingston University sports science student. But the conviction was quashed in an appeal ruling over the use of anonymous witnesses. Mayers pleaded guilty in May 2009 to manslaughter and was jailed for 10 years.

Coroner Dr Andrew Harris read out an investigation report from the Royal Barbados Police, which said Mayers and his cousin Samuel Joshua had rented jet skis for 30 minutes on the first day of their family reunion holiday.

He said: “Mr Joshua slowed down and Jordan reached him. Samuel was stationary. Given the rainy conditions, Jordan drove the jet ski towards Samuel but didn’t stop. He collided into the jet ski and was thrown into the water.”

Mayers’s cousin and two US tourists were unable to revive him. Dr Harris said there were concerns over renting out jet skis in bad weather, and whether the vendor, Ricardo Clarke, had a licence. But he said the Barbados authorities had not investigated this, or provided the court with the full autopsy report.

Mayers’s father Winston Trew, who was not on the holiday, said: “I keep on thinking that, if there was a lifeguard there, then Jordan might have been rescued and survived… If he didn’t have the head injury, he might not have drowned.”

Dr Harris concluded that Mayers died from a head injury caused by an accident, telling Mr Trew: “I know you have waited two years for this and I’m sorry I couldn’t give you more closure.”