Andrew Boyle, whose 1979 book "The Climate of Treason" triggered the expose of royal art adviser Anthony Blunt as a Soviet spy, has died.
He was 71 when he died of cancer at his home in London on April 22.
Boyle was convinced of Sir Anthony's complicity in the notorious spy ring that included Guy Burgess, Donald MacLean and Kim Philby, but could not prove it, and so referred to Blunt as "Maurice," in "The Climate of Treason."
Thatcher told the House of Commons that Blunt had confessed to security authorities in 1964 to being a Soviet spy while working for the British counterespionage service MI5 during and after World War II.
She said he had been granted immunity from prosecution in exchange for information that he gave about his colleagues.
Boyle first stumbled on Blunt's involvement when he visited Cambridge University in 1976 during the early stages of research for his book.
He established that Blunt had worked closely with Burgess to turn the proceedings of The Apostles, a secret society at the university, into a Marxist cell in the 1930s. Blunt died in 1983 at 75.
Boyle served in British military intelligence in the Far East during the latter part of World War II and after the war joined the British Broadcasting Corp. as a radio scriptwriter and producer.