Police were called to the 21-year-old Playboy heir’s apartment in Pasadena, California, after a call was made by one of Sinclair’s family, claiming that he’d attacked her.
A source said cops saw that Sinclair, 20, had bruises and that Marston admitted to having a confrontation with her, but denied hitting her.
But the source said Sinclair told police: “Marston had punched her, kicked her in the stomach and then refused to let her leave the residence.”
Lt. Jari Faulkner said Sinclair sought an emergency restraining order from Marston on Monday and was granted a five-day order so she could move out of the apartment, which she shares with him.
She was later photographed with a bruise on her arm, while she moved some of her belongings out of the flat.
Marston was arrested on Sunday night for misdemeanor domestic violence and was released on $20,000 bail soon after.
Marston’s dad Hugh commented: “If they care about each other, they’ll patch it up.”
Sinclair Tweeted: “There’s two types of pain in the world — pain that hurts you, and pain that makes you stronger. All of your positivity is giving me strength.”