A man has gotten himself into more trouble than he saw coming after he was found out to have forcefully had s*x with his girlfriend's sister.

A young man who r*ped his girlfriend’s twin sister claims it happened after he mistook her for her sister, a Metro UK report has shown.

According to the report, the 24-year-old man, from Melbourne, was sentenced to four years in jail after being convicted of rape and indecent assault.

He told police his victim was a liar and had made unwanted advances towards him but a court later heard he had told her that he had always fantasised about having s*x with her.

The victim had been staying with her sister and the 24-year-old after ending a relationship and was sleeping in the spare bedroom when the man walked in to speak to her.

He then pulled down her clothing and raped her, according to the Herald Sun, but later told his partner that he was sexually assaulted by her sister.

The man repeated his claim to police and told officers that he was confused because his partner and the victim looked identical to one another.

County Court judge Felicity Hampel told him: ‘That was a bizarre thing to say given you’d been talking to [the victim] about her, and her issues, for over an hour.’

The victim has reportedly become estranged from her twin following the attack and said she has attempted suicide more than a dozen times since.

She said: ‘All I have ever wanted was for him to say sorry and admit what he has done to me.’