Born in Lambeth, Nigel West was educated at a Roman Catholic monastery and London University. While still a student he worked as a researcher for the authors Ronald Seth and Richard Deacon, who both specialised in security and intelligence issues.

In 1977 Nigel joined BBC TV's General Features Department to make television documentaries, and he worked on the SPY! and ESCAPE! series. His first book, written with Richard Deacon, was based on the first series and was entitled SPY! Thereafter he was commissioned to write a wartime history of the Security Service, MI5, which was published in 1981, and since then he has averaged one book of non-fiction a year, including The Secret War for the Falklands released in January 1997.

He has concentrated on security and intelligence issues and his controversial books invariably hit the headlines. He was injuncted by the Attorney-General in 1982 and was served a Public Interest Immunity Certificate signed by the Home Secretary in 1987. He was voted 'The Experts' Expert' by a panel of other spy writers in the Observer in November 1989 and The Sunday Times has commented:

'His information is so precise that many people believe he is the unofficial historian of the secret services. West's sources are undoubtedly excellent. His books are peppered with deliberate clues to potential front-page stories.'

Nigel West often speaks at intelligence seminars and has lectured at both the KGB headquarters in Dzerzhinsky Square and at the CIA headquarters in Langley. He is now a member of the faculty at the Centre for Counterintelligence & Security Studies in Washington DC (www.cicentre.com).

His greatest coup was tracking down the wartime double agent GARBO, who was reported to have died in Africa in 1949. In fact West traced him to Venezuela, and they collaborated on GARBO, published in 1985. He was also the first person to identify and interview the mistress of Admiral Canaris, the German intelligence chief, and he was responsible for the exposure of Leo Long and Edward Scott as Soviet spies.

His recent titles include Crown Jewels, based on files made available to him by the KGB archives in Moscow; VENONA, which disclosed the existence of a GRU spy-ring operating in London throughout the war, headed by Professor J B S Haldane and the Hon. Ivor Montagu: and The Third Secret, an account of the CIA's intervention in Afghanistan. In Mortal Crimes, published in September 2004, investigates the scale of soviet espionage in the Manhattan Project, the Anglo-American development of an atomic bomb.

In 2005 he edited The Guy Liddell Diaries, a daily journal of the wartime work of MI5's Director of Counter-Espionage. He also published a study of the Comintern's secret wireless traffic, MASK: MI5's Penetration of the Communist Party of Great Britain, and a counter-intelligence textbook, The Historical Dictionary of British Intelligence.

He has lectured at the Smithsonian institute in Washington DC, speaks regularly for Hilton Special Events, on the QE2 and QM2, and for Seabourn, Regent Crystal Cruises. His topics include: GARBO: The Spy Who Saved D-Day; VENONA: The Greatest Secret of the Cold War; The Cambridge Five: The True Story of Guy Burgess, Donald Maclean, Kim Philby. Anthony Blunt and John Cairncross; Double Agents of World War II; The History of the British Secret Intelligence Service; James Bond: The Fact and fiction of 007; Combatting Terrorism: How the IRA were beaten in Northern Ireland; Enigma: Bletchley Park and the Codebreakers; Molehunt: The Search for Soviet Spies.

In 2003 Nigel West was awarded the US Association of Former Intelligence Officers' first Lifetime Literature Achievement Award.