The family of Italian designer Gianni Versace has distanced itself from a long-awaited US television series about his violent death.

The nine-part series, made by 21st Century Fox and premiering next week, stars Spanish actress Penelope Cruz and Puerto Rican singer Ricky Martin.

Versace was gunned down in 1997 at the entrance gate of his Miami beach mansion by serial killer Andrew Cunanan.

The Versace company "did not authorise and was not involved in the television series," it said in a statement on Monday.

The series had to be considered "an act of fiction", it said, given it drew inspiration from a book that was not authorised - Maureen Orth's 'Vulgar favours'.

A spokesman for 21st Century Fox had no immediate comment.

Versace founded his eponymous fashion house, famous for its Medusa head logo, in 1978. In 2014 US private equity firm Blackstone bought a 20% stake. Gianni's sister Donatella is artistic director and vice-president of the group.