Nelson Mandela's ex-wife Winnie is threatening legal action against the makers of a biographical film about her starring Jennifer Hudson.

The film is likely to detail the fraud, kidnapping and murder controversies that have surrounded the anti-apartheid leader's former wife.

Mrs Madikizela-Mandela, as she has been known since her divorce from Mr Mandela in 1996, is one of South Africa's most controversial and divisive figures.

She is revered in some quarters as the "Mother of the Nation" for her role in the struggle, the harassment she suffered from the white authorities, and her populist rhetoric that still appeals to South Africa's poor.

But for others she is reviled. She once notoriously declared that "with our boxes of matches and our necklaces, we shall liberate this country", referring to the preferred way of killing suspected informers in the townships, setting fire to a petrol-filled tyre around their necks, so ensuring an agonising death.