Britain said on Tuesday it was seeking the release of an elderly British man facing 350 lashes after being caught with homemade wine in Saudi Arabia, a sentence that his family said could kill him.

Karl Andree, 74, was jailed for 12 months in August last year but remains in prison awaiting further punishment for breaking strict Saudi laws prohibiting alcohol after police found the wine in his car, his family said.

"There were two sentences. The custodial sentence, which finished in August, and then there's the lashing sentence ... which I assume he's been kept in there because that hasn't been dealt with yet," his son Simon Andree told BBC radio.