The fiance and killer of the domestic violence murder victim Gabby Petito desperately called his parents and told them that she was “gone” weeks before she was discovered dead – yet they later shared messages expressing hope that search efforts for her would end in success, her family has alleged.

Petito’s parents, Joseph Petito and Nichole Schmidt, made the claim in a lawsuit that they are pursuing against Brian Laundrie’s family and their attorney in the latest chapter to a case that has generated international news headlines.

The Petitos, who amended the lawsuit with the new allegations on 30 November, have accused Laundrie’s parents as well as their lawyer of intentionally withholding information about their daughter’s murder, inflicting on them pain and emotional distress.