The family of a Briton jailed for life for smuggling heroin in Thailand has vowed to appeal against his conviction.

Julian Gilbey, an English language teacher from Sussex, was convicted of smuggling 4kg of heroin after being arrested at Bangkok's Don Muang airport last October.

A judge commuted the death penalty on account of Gilbey's earlier confession.

Gilbey's family, who live in Rothesay, in Scotland, has said all along that he was duped into carrying the drugs by an organised gang.

Drug smuggling can carry a death sentence

His sister, Karen Cameron, said important evidence that could clear her brother was ignored by judges.

She said: "It wasn't a fair trial. There was a lot of evidence that wasn't allowed to be heard in the court.

"The lawyer had asked the judge if he would hear the evidence or if he would let him have letters from here and he refused all the way."

Ms Cameron said evidence from a key witness, Australian John Care, has not been heard.

She said Care was arrested in Austria for smuggling drugs and told police that he also thought he was carrying diamonds.

"He immediately wrote a statement to the police saying that the following day the same thing was going to happen and that Julian was involved," said Ms Cameron.

She called for intervention from the UK Government and said an appeal would be lodged.

Mr Gilbey's MP expressed relief that the death penalty was not imposed but said he was concerned about the confession obtained.

Transferred to the UK

Alan Reid, Liberal Democrat MP for Argyll and Bute, said: "It has been written in Thai and presented to him.

"Under Thai law it should have been presented in English but Julian insists it was never translated for him."

Mr Reid added that, under an agreement, Britons convicted in Thailand could be transferred back to the UK after serving one third of their sentence and hoped that Mr Gilbey could be moved.

Gilbey, 35, arrived at the Bangkok court in manacles and flanked by armed guards to hear sentence passed.

He appeared with four co-defendants - a Dutchman, a Thai woman and two men from Nepal.

They were caught trying to smuggle 4kg of heroin from Thailand to Taiwan at the end of last year.

All four men were convicted and the woman was acquitted.