Mark Cuban was accused of sliding his hand down the back of a woman's pants and digitally penetrating her while they posed together for a photograph at the Barrel Room bar, in Portland, in 2011

Police transcripts reveal how billionaire Mark Cuban reacted when detectives confronted him over claims he groped woman while drunk in an Oregon bar.

The Dallas Mavericks owner was accused of sliding his hand down the back of a woman's pants and digitally penetrating her while they posed together for a photograph at the Barrel Room bar, in Portland, in 2011.

Police investigated at the time but later dropped the investigation citing lack of evidence.

Cuban has always denied he sexually assaulted the woman.

The matter only came to light this week after Portland's Willamette Week obtained the police records via a public records request. Those records also contain the full transcript of when detectives called Cuban to confront him on the allegations for the first time.

They recorded Cuban's panic and fear that he would be labeled a 'pariah' if the allegations were made public.

'Oh my Lord. Oh my f**king Lord. Oh, that's what you get for being nice,' he told the officer after hearing the claims. 'I put my finger in her vagina?! Are you kidding me?

'Unbelievable. I'm damned if I do and damned if I don't. I'm just gonna be like a pariah no matter what,' he continued, after denying the allegations. 'Nothing happened, but when you're high profile, it doesn't, it's never just about nothing happening.'

The married businessman and reality TV star began to spiral towards the end of the call, telling the investigator: 'There was no way to prove the truth… Oh Lordy.

'F**k me! I'm so f**ked!'

The investigation was later dropped and prosecutors, in a report explaining why they weren't pursuing the claims, wrote that 'there is no evidence to corroborate the complainant's statement and there is evidence contradicting the claim.'

The report also said the woman didn't want to proceed with the allegation.

But the alleged victim, now married and in her 30s, told Williamette Week, this week, she stands behind her claim '1,000 per cent'.

The woman explained that she had arrived at the bar - Barrel Room (pictured) - with her boyfriend, who suggested she try to take a picture with Cuban, who she claimed appeared very drunk

She added: 'I filed the report because what he did was wrong.'

In a recent email to the Associated Press, the billionaire again insisted he was innocent, writing simply: 'It didn't (happen).'

The woman described the night she arrived at the Barrel Room on April 22, at around 11.30pm, with her boyfriend and friends.

Cuban, who was in town for a playoff game the following day between his team and the Trail Blazers, arrived around 30 minutes later after watching a Lakers game on TV.

The woman said her boyfriend recognized Cuban and suggested she go and take a photo with him. Initially, she said she was reluctant, but by 2am, the woman and her friend ran into him at the bar.

Cuban, she said, appeared 'very drunk'.

The father-of-three, who is married to wife Tiffany Stewart (pictured with him in Washington in 2015), said that people 'hug' and 'grab' at him all the time

Cuban, a family man, lives in Dallas with Tiffany, daughters Alexis and Alyssa, and son Jake (pictured last year at the Kid's Choice Awards)

She said he agreed to pose for the picture, first putting his hand on her back.

But a detective, summarizing the woman's victim statement, explained in the reported case file: 'He then moved his hand down until it was on her buttocks.

'Cuban then pushed his hand down the back of her jeans and inside her underwear where he cupped his hand over her groin area and inserted the tip of his finger into her vagina.'

She reportedly told police two weeks later, including in her complaint seven photographs taken of her and Cuban.

The police report explains that in one of the pictures, she appears uncomfortable.

'Her teeth are clenched, eyes wider than the other pictures and brow raised showing a look of surprise and strain,' it said.

It was that photo, coupled with the woman's allegations, that led Detective Brendan McGuire to put in the call to Cuban on June 8, 2011, to tell the billionaire they'd received allegations that 'you did some inappropriate touching while at that club.'

'Are you serious?' Cuban replied, before responding that the bar was packed, and people were taking 'pictures left and right' so 'how could I inappropriately touch anybody?'

The father-of-three, who is married to wife Tiffany Stewart, said that people 'hug' and 'grab' at him all the time, before the detective informed him the allegations were more serious than that.

'The allegation is that she came up to you to get some pictures taken and while sort of doing [an] arm around each other picture-taking thing, you stuck your hand down the back of her pants and inserted your finger into her vagina,' McGuire said.

'Oh! Hell no!' Cuban replied. 'You don't think a hundred people would've noticed? I mean, she wouldn't say something right there and then and smack the s**t out of me? And while we're… oh hell no. [laughs] Are you kidding me?'

McGuire asked if Cuban 'categorically' denied the charges, which he did, before demanding to know how much he'd had to drink the night alleged assault occurred.

The 59-year-old conceded he'd been drinking but said he remembered the entire evening, adding: 'I wasn't sloshed but I wasn't sober either.'

'Oh my God, this is just [going to] kill me if she does something,' he added. 'There was tons of people around. I kept on not even head butting but chest bumping Kevin Love right there. There's tons of people, all those bartenders right there were talking to me the whole time. I was not alone at all with anybody.'

The detective informed Cuban he had seven cellphone pictures of the Shark Tank star with the alleged victim. In two, it appeared that his shoulder dipped and his arm appeared to be below her waist, McGuire said.

'Are you kidding me?' Cuban responded in shock.

'If what she is alleging were true,' McGuire said, 'that would be a sex abuse in the second degree, which is a felony.'

'Oh my Lord,' Cuban said. 'Oh my f**king Lord.'

Dallas Mavericks owner Mark Cuban, left, (pictured with Eduardo Garcia, member of the Mike Garcia boxing team, in 2013, in Dallas) insisted again this week he was innocent, writing simply: 'It didn't (happen)'

The Mavericks owner demanded to know why the woman hadn't told anyone at the time if the allegations were true, but was informed that she claimed she told her friend and her boyfriend.

'There's just no way. Just no way. If she told five friends right there and then, then that's what they're gonna tell the judge and I'm gonna be f*****. Oh my God. [sighs] I don't know what to do,' Cuban responded.

Cuban denied the allegation at the time, passed a polygraph test and hired a lawyer who cited the opinion of two paid experts, urologists at George Washington University Medical School, who made the rather bizarre claim he could not have sexually assaulted the woman because his hands were too big to penetrate her vagina.

The publication of the allegation came two weeks after a Sports Illustrated account that portrayed a hostile work environment for women in the front office of the Mavericks.

The report included claims of inappropriate sexual conduct by former CEO Terdema Ussery and raised questions about what Cuban knew and when.

DailyMail.com has reached out to Cuban's lawyer Stephen Houze for comment.