The Guardian newspaper reported Wednesday that Peter Martland of Cambridge University discovered that Mussolini was paid 100 pounds a week by Britain in 1917 - equal to about 6,000 pounds ($9,600) today.
The late Samuel Hoare, in charge of British agents in Rome at that time, revealed in his memoirs 55 years go that Mussolini was a paid agent. Martland found more details in Hoare's papers, including that Mussolini also sent Italian army veterans to beat up peace protesters in Milan, a dry run for his fascist blackshirt units.
"The last thing Britain wanted were pro-peace strikes bringing the factories in Milan to a halt. It was a lot of money to pay a man who was a journalist at the time, but compared to the 4 million pounds Britain was spending on the war every day, it was petty cash," The Guardian quoted Martland as saying.
The salary detail also was in historian Christopher Andrew's newly published history of the British intelligence agency MI5, to which Martland contributed.
In 1917, the future Italian dictator was editor of the Il Popolo d'Italia newspaper, which campaigned to keep Italy on the allied side in the war.