Scotland Yard detectives are to fly to the Caribbean to investigate links between the spy writer and former Tory MP, Rupert Allason, and a publishing company.

The investigation, which could lead to his arrest over perjury claims, follows a high court case last year when the judge described Mr Allason as a "profoundly dishonest man".

Mr Allason, who uses the pseudonym Nigel West, had sued the publisher Random House over a book, The Enigma Spy, the posthumous biography of John Cairncross, the "fifth man" in the Cambridge spy ring.

Mr Allason claimed copyright, saying that he wrote the book.

After hearing testimony from Mr Cairncross's widow, Gayle, Mr Justice Laddie accused him of advancing a case that was a "tissue of lies".

The judge, who awarded costs of £200,000 against Mr Allason, also pointed to evidence the writer gave in court denying that he was a director of an offshore publishing company, St Ermin's Press.