The verdict of a man found guilty of rape for inserting a beer bottle into the vagina of a performer at a buck's party sex show could set a new legal precedent.

Key points: Kevin Willcocks was found guilty of rape for inserting a beer bottle into the vagina of a woman who was performing a buck's night sex show

Kevin Willcocks was found guilty of rape for inserting a beer bottle into the vagina of a woman who was performing a buck's night sex show Defence lawyer Mark Thomas said his client has struggled to find similar cases in Australia

Defence lawyer Mark Thomas said his client has struggled to find similar cases in Australia Crown prosecutor Stephen Geary said it had been difficult to decide where this assault sat on the scale of sexual offending and that the sentence should send a strong message to the public

Kevin Willcocks, 41, was on Thursday handed a majority guilty verdict in the NT Supreme Court over the assault.

The challenge Justice Dean Mildren will now face in sentencing was made clear to him from both sides of the bench during submissions for Willcocks's case about the actions that occurred at a buck's party in the Darwin rural area in 2017.

Willcocks's defence lawyer Mark Thomas said he struggled to find similar cases like this in Australia.

Mr Thomas urged Justice Mildren to consider that the bottle was inside the woman for just two seconds or less, the buck's party context and the level of intoxication.

He also said Kevin Willcocks had four children, no history of violence, no prior convictions other than some historic traffic offences and that the incident was "out of character".

In his submission, Mr Thomas also argued that there were inconsistencies in the woman's evidence and two witnesses had contradicted parts of her version of events.

'It's a difficult one': Crown prosecutor

Senior crown prosecutor Stephen Geary agreed that Justice Mildren had a challenging decision on his hands, considering the circumstances.

"It is a difficult sentencing matter, no one can take issue with that," Mr Geary said.

"Where this sits on the scale of sexual offending is a difficult one."

Mr Geary said the sentence must send a message to the public that a "woman in the position of [the victim] needs to be respected at all times and there are modes of behaviour that are always unacceptable."

Justice Dean Mildren interjected: "not just unacceptable, it's illegal".

The prosecutor said the crown accepted that it was not a premeditated act, and that it was "spur-of-the-moment, impulsive, albeit criminal".

Mr Geary also referred to a victim impact statement, reading to the court that the woman involved said following the verdict she now felt "validated" and "no vindictiveness" towards the accused and that the sentence was entirely up to the Justice.

He told the court that it was a serious assault that breached her personal space and liberty and was humiliating.

Justice Mildren will deliver his sentence on Monday.