Wealthy couple accused of forcing a woman into a threesome so violent it landed her in hospital.

A wealthy New York couple has been accused of forcing a woman into a violent threesome that left her covered in bruises and bite marks.

Anne Hardcastle, 27, and Michael Taylor, 45, are facing object rape and sexual assault charges over the incident, which occurred after the Sundance Film Festival in Utah in January.

According to The New York Daily News, the alleged victim, aged in her 20s, presented to a medical centre shortly after the suspected assault with scratch marks all over her upper body, suction marks on her neck, bruises and bite marks on her arm, a bitten lower lip and acute vaginal pain.

Hardcastle and Taylor, a principal at a financial firm, were arrested in New York on Friday and are being held without bail as they await extradition to Utah.

According to court documents cited by The New York Daily News, the couple met the alleged victim at a bar in Park City, where they bought her three rounds of tequila.

They then reportedly invited her to a Sundance after-party, but detoured to their hotel room where they gave her ecstasy, more alcohol and suggested a threesome.

The victim told prosecutors that she then texted two friends to ask for a lift home, but then “everything went black”.

She fled to a friend’s house the next morning, after she awoke to find Harcastle in bed beside her.

"She wouldn't hurt anyone." Ed Hardcastle and his daughter, Anne. Image: Instagram.

The couple may never have been identified had Hardcastle not sent the woman an Instagram request just a few hours after the alleged assault.

The messages she exchanged with the victim over the next few months provided prosecutors with evidence to pursue charges against her and Taylor.

Among them, was a message that allegedly read, “You said you liked it rough and so I gave you what you wanted," reports The Daily News.

Taylor's father, Ed Taylor, told the paper he was shocked by news of his daughter's arrest.

“The last thing she would do is engage in this sort of activity. She’s not that sort of person at all. She wouldn't hurt anyone,” the 62-year-old said.

Mr Hardcastle said his daughter had been dating the former pro hockey player for a couple of years.