The prime suspect in the murder of police officer Yvonne Fletcher was given a letter from Tony Blair’s government reassuring him he was not wanted over the killing, his lawyer has told the Telegraph.

Saleh Ibrahim Mabrouk was informed he was not a suspect as long ago as 2002 at a time when Britain was forging close relations with Muammar Gaddafi’s regime.

However, a 192-page review of the police evidence seen by the Telegraph repeatedly identifies Mabrouk as one of the suspected ringleaders of a “pre-arranged plan to cause death”.

Mabrouk, who lives in Berkshire, was finally arrested on suspicion of conspiracy to murder in 2015 but the prosecution was blocked on Tuesday on grounds of “national security”.