The Downing Street memo itself was an official record of a meeting of the British war cabinet held in July 2002.
The second set of two documents, including the Downing Street memo itself, were obtained while he was working for the Sunday Times.
This was subsequently televised and updated in 2011 as The Secrets of Station X: How the Bletchley Park Codebreakers Helped Win the War.
He then joined the Daily Telegraph where he worked as an assistant foreign editor, then a news reporter and finally Defence Correspondent.
His first novel Ritter: No Man Dies Twice, a detective/spy thriller set in Nazi Germany during the Second World War was published in February 2022.