The trial of Jason Lee, a former Goldman Sachs managing director, accused of rape, assault and sexual misconduct of a 20-year-old Irish student in the Hamptons, Long Island, two summers ago began with a graphic description of the assault.

The court heard how allegedly the former Wall Street banker had forced his way into a downstairs bathroom, knocking her over and pinning her down as he raped her. The attack was only ended after the Irish woman kneed him in the groin and escaped.

They also heard, from the prosecutor and the first officer on the scene, that Lee (38) had tried to send a police woman away from the beach house on the night of the attack saying it was “no big deal.”

He has pleaded not guilty to the crimes claiming they had consensual sex after meeting at a nearby nightclub and returning to the a friend’s $33,000-a-month beach house. The alleged attack took place in the early hours of August 20, 2011, at a party in the Hamptons.

The Irish student has returned to New York to be present at the trial in Suffolk County Court in Riverhead, Long Island. Lee was joined in court by his wife, Alicia.

Kerriann Kelly, state prosecutor told New York State Supreme Court Justice Barbara Kahn, in the non-jury trial, that Lee was “a man who wanted one thing and one thing only - and that was sex and he used her to get it”.

She said that the Irish student and Lee came “from such different worlds that they could have been from different planets.”

Kelly said “What you see is not always what you get…What you see in the court room this morning is a defendant dressed in a very professional suit, his hair is nicely combed. he is copiously taking notes as I speak.

“That's not the same individual the victim encountered in the early morning of August 20 2013. Not even close.

“What she encountered was a man who wanted one thing and one thing only, and that thing was sex. He used her to get it.”

Lee had left his wife in New York City, 80 miles away, to celebrate his 37th birthday with his friends. The Irish university student was in the US on a J-1 visa. She had been visiting her brother who was working in Montauk, on the south fork of the island, nearby.

Kelly told the court that Lee had brought the woman, her female friend and her brother back to his friend, Rene Duncan’s, East Hampton house, after a night of drinking and dancing at Georgica nightclub.

She said the two Irish girls had removed their clothing to swim in their underwear in the house’s pool. Lee “stripped down to nothing” and told the “I skinny-dip - that’s what I do.” The girls felt uncomfortable. They later continued drinking in the kitchen.

At about 6am the student went to the downstairs bathroom to put on her dress and was followed by, still naked, Lee. As she entered the bathroom Lee tried to follow her in. Kelly told the court the Irish student said “What do you think you are doing” or words to that effect.

He pushed the door so hard that she left her finger prints on the door. The Irish student was not strong enough to keep him out.

She fell backwards and hurt her hip.

Kelly told the court “He had her exactly where he wanted her - on the floor, on her back.”

She tried to fight Lee off but could not. Kelly told the court that twice Lee screamed “shut the f.... up” and proceeded to rape her, covering her mouth so hard that the student could not bit him.

The attack continued until the student managed to knee Lee in the genitals.

The Irish student was left “hysterical and crying” after the attack she could barely speak” or “say what was wrong with her”.

Kelly said “He had no regard for her.

“He had no condom and the 37-year-old Jason Lee you see before you here had no regard for the 20-year-old Irish girl who was just visiting (her brother).

“He took advantage of her because he wanted to have sex and because he was going to do whatever he had to do to get it.”

Upstairs the homeowner, Duncan, had called the police with relation to the alleged theft of his SUV truck. A friend of the Irish student’s brother had taken it to drop two local men home.

The recording of the 911 call was played in court. As Duncan is speaking the woman’s brother comes on the phone saying “I have got another situation I need to sort out, a more important situation than a truck.”

When East Hampton police officer Sarah Mortensen arrived at the beach house Lee greeted her saying “We’re good; you can go, we got this under control; the car is not an issue.”

Kelly told the court he was “trying to get rid of the police” telling her that there “no big deal.”

The student’s brother insisted there was a “bigger issue.” The Irish woman told the policewoman, still in her car, that she had been raped. At this point Lee disappeared and was “not seen again for over two hours.”

He was found “curled up in a fetal position” in the back seat of his Range Rover. He told the police “I am embarrassed. I am drunk. I fell asleep.”

However, while he was hiding he had called Uber, the online taxi company, twice. Kelly said he was “trying to get out of there.”

The Irish student had an hour-long medical examination. A nurse, with experience in treating sexual assaults, said she found an injury to the student’s vaginal area, bruises and a long scratch almost the length of her leg. She said these injuries are “consistent” with her allegation of rape.

The dress and underwear she wore that night only turned up seven months later via an investigator hired by Lee. There was “no explanation for where it had been.”

Also on Wednesday Andrew Lankler, Lee’s defense lawyer, gave his opening statement. He said this case is “the product of a rushed investigation” and said there were “critical inconsistencies” in the statements provided by the woman, witnesses and even the police.

He brought to the court’s attention a photograph of the Irish student and Lee taken at the nightclub, earlier that even. He said “It was entirely consistent with the circumstances under which consensual sex occurs, perhaps regrettable consensual sex.”

Lankler went on to say that the student’s friend and brother would testify that they did not hear any sounds from the downstairs bathroom, although the prosecution alleges that both Lee and the student screamed.

He said the bruise on the woman’s hip was from a pre-existing injury and not from the struggle at the bathroom door. He also pointed out that Lee did not have “a scratch on him.”

Mortensen, the first officer on the scene, testified. She said when she arrived at house Duncan was “highly intoxicated, slurring his words” and complaining about his missing car.

Lee appeared at her car window saying there was no problem and that she could go. The Irish student’s brother told the officer her sister was really upset and asked the officers to figure out what was going on.

The police officer spoke to the Irish student in the car with the windows up.

Mortensen said “She was upset, she couldn’t sit still, she was fidgeting.”

The officer told the court that the Irish student had said “the Chinese man had raped her.”

When Mortensen looked up Lee was no longer there.

The trial continues.