A trailer for the new Nelson Mandela movie starring Idris Elba has been released as the frail freedom fighter enters his seventh week in hospital.

Mandela: Long Walk to Freedom stars the actor better known to most as Stringer Bell from TV's The Wire in the lead opposite Bon girl Naomie Harris as Winne Mandela and is produced by the Weinstein Co.

Directed by Justin Chadwick, the film is already generating plenty of Oscar buzz for Elba and the movie is based on Mandela's own memoir. It was filmed with the blessing of the 95-year-old statesman and it traces his life from childhood to his inauguration as president of South Africa.

While the trailer portrays him as a revolutionary, public enemy, outlaw, radical and liberator it doesn't shy away from his private life with Winnie telling him: "I heard you had other girlfriends, but I'm different."

The trailer was released to coincide with Mandela's 95th birthday which came as he entered a seventh week in hospital, with his supporters heartened by news that the anti-apartheid icon is showing signs of improvement.

Biker gangs cleaned streets, volunteers painted schools and politicians spent 67 minutes on worthy projects - all to mark Mandela's 67 years of public service.