Sean Bean played Andy McNab in the TV film Bravo Two Zero
The BBC is making Andy McNab's best-seller Boy Soldier into a film after securing the rights to the book.
Its sequel Payback, also co-written with Robert Rigby, has been acquired as part of the deal.
The children's books are the first in a series of four about Danny and his struggle to join the army.
Former SAS soldier McNab's best-selling book Bravo Two Zero, based on his experiences in the Gulf War, was made into a TV film starring Sean Bean.
The soldier-turned-author left the SAS in 1993 as the most decorated soldier in the British Army at the time.
The real identity of McNab, which is not his real name, is kept secret and whenever he appears on television his face is always hidden in shadow to disguise him.
After writing the non-fiction book Bravo Two Zero he then turned his hand to fiction, penning more than 10 novels.
He and writing partner Rigby are currently adapting Boy Soldier for the film version.
Rigby is a TV scriptwriter who most notably works on children's drama Byker Grove. Boy Soldier and Payback have sold more than 110,000 copies since they were published in 2005.
"We are delighted to be renewing our relationship with Andy after Bravo Two Zero," said David Thompson, head of BBC Films.
"Boy Soldier is both a fantastic thriller and a moving story of the relationship between a boy and his grandfather.
"The project also represents BBC Films' commitment to make more ambitious films for wider audiences."