The family of a British engineer imprisoned on “trumped-up” charges in central Africa has pleaded with the Government to do more to win his release.

The family of Peter Huxham, who has dual South African nationality, say Equatorial Guinea has made him a “political hostage” in retaliation for the South African courts seizing luxury villas and a superyacht belonging to the vice-president.

The 55-year-old offshore oil engineer has been held along with a colleague for nearly 750 days in a case condemned by the United Nations as illegal.

The UN’s body on arbitrary detention has issued a lengthy ruling saying the men were denied a fair trial and should be immediately released.

Diplomatic missions have failed

However, the government in Equatorial Guinea is refusing to comply and high-level diplomatic missions to the country have failed to win their release.

Mr Huxham’s family say his mental health has suffered in prison, and they fear he will not survive his 12-year sentence.

Kathy McConnachie, his fiancée, told The Telegraph: “I would just like both governments, South Africa and the UK, to try and do more. We need them home. Our lives are very empty without these men at home.”