Her lawyer Carlo Dalla Vedova says, "She was shocked. She felt sick and she almost fainted because of what it showed. She is very upset at how she is being portrayed in this film."
Amanda Knox, who is appealing against her conviction, is believed to have seen the footage while watching a TV news programme in her Italian jail cell.
The preview depicts Amanda Knox taking an active role in the murder, with a police official claiming she "orchestrated" the crime as part of a kinky sex game.
He says, "Under the angel face, she is capable of anything."
Dalla Vedova has threatened legal action against bosses at network Lifetime if they air the film, which is due to be screened on 21 February (11).