Lake Mungo

Sixteen-year-old Alice Palmer drowns while swimming with her family at a dam in Ararat, Australia, Australia. Following the tragedy, her teenaged brother Matthew sets up video cameras around the house to record what seem to be images of Alice's ghost appearing in the family home. It's discovered that Matthew was actually setting up the "sightings" of his dead sister to give the family reason to exhume her body and give his mother closure. However, upon closer review, one of the hoax videos captures Alice's bedroom being searched by Brett, a neighbor for whom she had worked as a babysitter. After her own search of the bedroom, Alice's mother finds a hidden videotape showing Alice in a sexual encounter with Brett and his wife.