Calvin Denker was seen joining in with the song Cruel Summer in footage from one of Swift's shows in Minneapolis, Minnesota, at the end of June.

However, he has now told followers on TikTok that he was subsequently fired by BEST, the company he was working for.

While the company did not have a problem with his singing, bosses were apparently unhappy as he had passed notes out to crowd members asking them to send him any photos or footage showing him in front of the singer while she was on stage.

"Long story short, I was fired for it," Mr Denker told his followers in a video posted on social media. "My former security company said that they had a rule against taking photos with any of their performers...

"Every photo of me from that night was from behind the barricade, like any other photo from a fan would be. I never took my own phone out. And above all else, I made sure that Taylor Swift was safe and all the fans had a good time."

He finished his message by asking followers to refrain from "sending any hate to this company... I still got to work one of the coolest concerts ever... so that is fantastic. And I hold no grudges against my employer".

After footage of Mr Denker went viral, he released a video explaining why he wanted the job and how he asked fans for photos.

It appears his former employer came across this and realised he had broken their rules.

'I wasn't allowed to turn my back'

He said: "So five years ago, I went to [Swift's last tour] Reputation with my then girlfriend, now wife, who wasn't the biggest fan of Taylor Swift at the time, so I kind of had to drag her along.

"But I got to talk to a lot of the security guards that night and learn about what positions they can work and how they get to go to a lot of these concerts and any of the sporting events in Minneapolis. And that sounded so cool to me."

Mr Denker said Swift gigs were always the "goal" when he got the job, adding: "When she announced her Eras tour, I was so excited and I signed up as soon as I possibly could."

He said he was "amazed" on the first of Swift's shows in Minneapolis as the "fans were so loud and Taylor was phenomenal".

Read more:
Swift 'gives out bonuses of $55m'
Shake It Off performance hits earthquake levels
The music mogul who bought Taylor's back catalogue

However, Mr Denker explained: "I wasn't allowed to turn my back to the crowd and really watch Taylor perform... After night one, I was realising how close Taylor Swift was getting to me so I really wanted to get a photo to document it.

"I handed out these little pieces of paper that said I wasn't allowed to have my phone out but if Taylor Swift comes right behind me, please take a photo of me and text it to my number.

"I handed this out to a couple of people in the front row for night two, and they were really kind and really sweet about it."

Sky News has contacted BEST for comment, as well as representatives for Swift.