A MAN jailed for life for murdering a Swansea Valley couple on their Caribbean honeymoon has stabbed another inmate in prison, it has emerged.

Kaniel Martin was one of two men convicted in July of the killing of newly-weds Ben and Catherine Mullany on the holiday isle of Antigua.

Police have now revealed he stabbed a fellow prisoner during an incident on December 30.

A spokesman said: “An inmate was stabbed by Kaniel Martin. It’s a serious offence and the police will deal with it.

He added Martin used “a sharp implement”

and the 21-yearold victim was treated in hospital for “serious but not life-threatening”

injuries.

Mr and Mrs Mullany, from Rhos, Pontardawe, were shot in Antigua in July 2008, just a fortnight after their wedding.

Martin and Avie Howell broke into the couple’s beachside hotel chalet before shooting them both in the head and escaping with a digital camera, mobile phone and a small amount of cash.

Less than two weeks later, the pair went on to kill a local shopkeeper in near-identical circumstances.

Subsequent scientific examinations led police to link the gun used by the defendants with both crimes.

In July, Martin and Howell were found guilty but avoided the gallows after the judge handed out three consecutive life sentences.

They are due to stand trial later this year for killing two other people.