In 2013, singer Taylor Swift accused radio host David Mueller, who was invited to a meet-and-greet backstage at the Pepsi Center in Denver of pushing his hand up the back of her and assaulting her as they posed for a photo. Mueller has denied any wrongdoing and this week the two will go head-to-head in court over the alleged assault.

According to court documents, Mueller, who was with his girlfriend at the time of the alleged incident, "Intentionally reached under her skirt, and groped with his hand an intimate part of her body in an inappropriate manner, against her will, and without her permission."

Swift said, "As soon as he grabbed my a**, I became shocked and withdrawn and was barely able to say 'thanks for coming', which is what I say to everybody. I couldn't get the words out, it was like somebody switched the lights off in my personality. So it was pretty quick that he was gone after that."

This case is set to be one of the most high profile celebrity trials of the year and this is everything you need to know.

13 He accuses her of lying 

Mueller has accused Swift of making up the claims she was assaulted and he has since been demanding the entire case is thrown out of court. When he attended the court of August 4th, he told the judge the claims were a "complete fabrication" and he denied all allegations of any wrongdoing.

Mueller admitted the only contact he had with the star was "his hand appropriately touched Ms Swift’s hand", according to court papers obtained by the Mail Online. He also revealed that he brought his girlfriend, Shannon Melcher, along as his guest to the backstage meet-and-greet and that his interaction with Swift "remained pleasant as she bid them goodbye."

His girlfriend, at the time as they have since split up, will testify about the incident and also Mueller's character during the trial.

12 She felt "frantic, distressed and violated" 

According to an account by Mueller, once he was accused of the assault he told security staff: "Please call the police. I didn't do anything." Following this, Swift still posed for photos with a dozen of her fans and later, under a lot of distress, went on to perform in front of a 13,000 strong crowd. During her testimony, she recalled feeling very "frantic, distressed and violated."

The Shake It Off singer said, "Right as the moment came for us to pose for the photo, he took his hand and put it up my dress and grabbed onto my a** cheek and no matter how much I scooted over it was still there. It was completely intentional, I’ve never been so sure of anything in my life. I remember being frantic, distressed, feeling violated in a way I had never experienced before. A meet-and-greet is supposed to be a situation where you’re thanking people for coming, you’re supposed to be welcoming people and for someone to violate that hospitality in that way, I was completely stunned."

11 He tried to sue her for $3 million 

In 2015, Mueller was fired from his $150,000-a-year "dream job" at 98.5 KYGO radio as a DJ following the allegations of assault from Swift. His lawsuit stated, "The contention that Mr Mueller lifted up Ms Swift's skirt and grabbed her bottom, while standing with his girlfriend, in front of Ms Swift's photographer and Ms Swift's highly trained security personnel, during a company sponsored, VIP, backstage meet-and-greet, is nonsense, particularly given that Ms Swift's skirt is in place and is not being lifted by Mr Mueller's hand in the photograph."

Mueller demanded $3 million in damages for losing both his job and his apparent good reputation. Swift's legal team argued, "Mueller did not merely brush his hand against Ms. Swift while posing for the photograph. He lifted her skirt and groped her."

10 He has destroyed important evidence

US District Judge William Martinez is already aware that Mueller has destroyed important evidence ahead of before the trial - something which the radio host has been sanctioned for. The court heard that Mueller admitted to destroying a laptop, cell phone, iPad and computer which all held an important recording which should have made it to trial.

It is believed that the account Mueller gave during the phone call did match the story he told investigators. Martinez ruled that despite the recording not being available, Swift's lawyers can still ask Mueller questions about it during the trial. Court papers read, "He made the decision - inexplicably, in the court’s view - to alter the original evidence and to present his lawyer with only 'clips' hand-picked from the underlying evidence."

9 She has photographic evidence

Swift alleges that she has a photograph that will indefinitely prove her case for assault. As the incident took place during a photo opportunity during a meet-and-greet she had her security team seal the photo in a bag for evidence. However, that said picture was then leaked to TMZ online and the story about the assault went public shortly after.

Swift's management team said they had no intention whatsoever of the picture going public, as they stated, "We did not want copycats and one-uppers abounding. And that happens in our world. These people all tend to escalate. I've watched what happens with these files and individuals."

Her legal team said, "Ms. Swift knows exactly who committed the assault – it was Mueller – and she is not confused in the slightest" and that the photo was their most "damning evidence."

8 You can actually attend the trial

The public can attend the Mueller vs Swift trial as there are 32 seats available in the public gallery. Fans were already queuing during the early hours of the morning to grab a seat - but they might in luck when it comes to grabbing a seat as the queue wasn't that long. There are also a further 75 seats available in the overflow room which have cameras linked to the trial as it happens.

One fan named Scott McLean tweeted, "Surprisingly few fans in line to get to the courtroom today. I counted 22 people with a half hour ago." Swift has been keeping a low profile in New York City during the run up to the trial and she has not been interviewed directly by the media about the proceedings.

7 He has already given media interviews 

Usually, those involved in high profile people cases such as these are quite guarded over exactly what they say before a pending trial. But Mueller has decided to go fully public with his side of the story. Late last year, he told iHeart's Mojo In The Morning radio show, "I've never had my day in court. I've never been inappropriate with a woman in my life, I want my reputation back."

When discussing the leaked photo, he explained, "I was just trying to get my right hand around Taylor. It is clear her skirt is in place and is not being lifted (and) the image in the photograph of Ms Swift with (his ex-girlfriend) speaks for itself." Swift's legal team have said they plan to remain "discreet and quiet and confidential" throughout the trial.

6 She will appear in Colorado court to testify

It was initially unknown whether Swift would personally appear in court during the trial which is currently taking place in Denver, Colorado. She has agreed to appear and give her testimony in person as well as remaining present throughout the trial which is expected to last nine days.

The singer arrived with her mother, Angela Swift, opting for a pulled back bun and although cameras are not permitted in the courtroom there have been several sketches of Swift giving her testimony. Her attorney told the court, "(Swift) is taking a stand for all women" as this is an assault "in the work place." He continued, "A woman is assaulted. She reports it and she gets sued…it doesn't make sense. She's trying to tell people out there that you can say no when someone grabs you no matter who they are."

5 The jury selection was a tricky process

For trials that involve such high profile celebrities, it means selecting the jury will be a tricky process. In this trial, jurors were asked to fill out a 15-page questionnaire which asked if they had been inappropriately touched themselves, been falsely accused of inappropriately touching another person, or if they were fans of either Swift or Mueller. They were also asked if they had even seen the photograph of Swift and Mueller together which was published on the TMZ website.

According to reports, one juror was dismissed because she found Swift "petty and dishonest." Another was dismissed because they had a close friend who was assaulted and could not be impartial. Finally, the jury was selected and a total of eight jurors - two men and six women - were selected from a group of 60.

4 She is not the first to be assaulted by a fan

Swift is not the first artist to be groped by fans. Rapper Iggy Azalea had previously spoken out about being assaulted by fans during her live gigs. During an interview with New York City radio station Hot 97, she revealed that when she performs she now wears two pairs of underwear and tights. She even added that she has had to stop crowd surfing after suffering a string of assaults.

The Fancy rapper also revealed that weeks before her gigs she receives "lurk" tweets from fans warning her that she will be violated. She said, "I will get lurk tweets for like a week before my show. That's a violation. I don't actually like that stuff. They think I'm real sl***y." She also revealed that girls do exactly the same, adding, "Girls will try to do it more than guys 'cause girls think it's cool."

3 She is being accused of playing the victim 

Swift got a bad rep last year following the scandal involving her, Kanye West and Kim Kardashian. To cut a long feud short, West called Swift last January to ask if she minded lyrics in his song about him making her famous (because of the MTV 'Imma let you finish' scandal). Swift replied the lyrics "didn't matter" to her and that "if people ask me about it, I think it’d be great for me to be like, 'Look, he called me about the line before it came out. Joke’s on you guys! We’re fine.'"

When West released the song, Swift then complained about how offensive the song is and how it attacked her personally. Cue the greatest shade Kim Kardashian has ever thrown, as she had recorded the conversation between her husband and Swift then released it to the world as proof. Many people believe this is just another case of Swift playing her victim card once again.

2 She previously helped Ke$ha through her assault

Last year, singer Ke$ha was denied a preliminary injunction against Dr Luke's Kemosabe Records at Sony Music who she accused of harassment and misconduct in the work place - claims the producer completely denies. Ke$ha was too anxious to return to work but with bills to pay she was stuck in a bad place.

Then Swift donated $250,000 to help with Ke$ha's "financial needs" and as a "show of support." The donation was intended to be silent until it was advertised on Twitter by Demi Lovato who ranted: "Not everyone has 250k to just give to people. Would love to but I didn't grow up with money and def haven't made as much as her. At least I speak up about s*** that's uncomfortable to talk about rather than trying to be politically correct 24/7." Seems you just can't keep everyone happy.

1 She will donate any money to victim's support

Swift is suing Mueller for $1, however, if Mueller is found guilty then any victim support paid she has said will go to charities supporting those that have also been assaulted. Her legal team said, "I think that too often we see women who don’t have all of the power and influence of Taylor Swift assume that sexual harassment is the price of a paycheck."

According to studies, 40 percent to 70 percent of women have experienced some kind of sexual harassment in the workplace and Swift hopes this now high profile case will raise awareness surrounding this issue. As this is a civil suit and not a criminal case, Swift must show clear evidence she was assaulted rather than prove her case beyond a reasonable doubt.

Sources: bbc.co.uk, TMZ.com, people.com