Sean Bean starred in the BBC adaptation of Bravo Two Zero

McNab has sold the rights to all four of his novels including the bestseller Bravo Two Zero which, was previously adapted by the BBC.

The former soldier was the UK's most highly decorated serving soldier when he left 22 SAS Regiment in 1993.

On an SAS operation behind Iraqi lines during the Gulf war, the patrol McNab was leading was attacked.

Three members died, one escaped to Syria, and four - including McNab - were captured and tortured.

Andy McNab is not his real name, and he keeps his visual identity secret after receiving death threats.

He served in B Squadron 22 SAS for nine years and worked on covert operations worldwide, including anti-terrorist and anti-drug operations in the Middle East and Far East, South and Central America and Northern Ireland.

McNab has been slated as a co-producer on the future film, alongside Bonnie Timmermann, who has cast more than two dozen feature films.

The White House is the fictional target in Crisis Four

The pair met while working on Michael Mann's film Heat, where McNab worked as a technical advisor showing the stars how to handle weapons.

McNab's publicist said: "The film is still set to go ahead as the novel is basically about the fight against terrorism and good winning over evil."

Miramax confirmed that it had bought the rights to all four books, including his next novel Last Light, out on 4 October.

A spokesman told BBC News Online: "We bought the film rights to Crisis Four before the events of 11 September.

"There may have to be some adjustments made to the script and there will be a sensitivity involved in adapting it.

"It is still in the development stage and so far there is no date set for the start of production."