Aaliyah -- Family Vows To Torpedo Biopic

Aaliyah's family is on the attack against "Lifetime" ... vowing to stop production on her biopic.

Lifetime plans to start filming this summer ... chronicling the R&B singer's life and tragic death. 17-year-old Disney actress Zendaya has been cast as Aaliyah -- who died in 2001 in a plane crash.

Aaliyah's uncle and former manager, Barry Hankerson, tells us the family is pissed that no one from the network contacted them about the movie.

Hankerson says the family will block any attempt on Lifetime's part to use any of Aaliyah's music. He says the family has hired a lawyer and will do everything they can to block release of the flick.

The family is not opposed to a big, theatrical film, but thinks a TV movie is too small for someone as big as Aaliyah.

We called Lifetime ... so far no response.