Glastonbury attendee and teenage viral star Alex Mann has responded to speculation that his recent spontaneous performance with Dave at the festival was deliberately staged.

Over the weekend, Alex was pulled up out of the crowd and onto the stage with Dave during his set, to rap AJ Tracey’s verse in the track Thiago Silva, only to wind up going viral when he delivered a note-perfect rendition.

After being posted on the BBC’s Twitter page, the clip has already been retweeted more than 12,000 times in just a few days, with some even suggesting Alex’s supposedly impromptu performance was too good to not have been rehearsed.

However, after being tracked down by The Guardian, the 15-year-old has insisted the clip is legit.

“It was 100%. Completely just happened,” he told the newspaper. “I have only ever seen [Dave] once before at a show in Bristol.”

On the fated moment he was pulled up on stage, Alex added: “I’m not sure what was going through my head. I was so nervous. I thought: ‘What if I mess up?’ But then I went on stage and performed and it felt so good.”

Dave frequently pulls fans up during his show to perform the verse in question, spotting Alex in the crowd and pulling him up based on the fact the football strip he was wearing featured footballer Thiago Silva’s name.

As well as his own set, Dave was also invited to perform during Stormzy’s headlining set on the Pyramid Stage on Friday night, alongside his fellow grime star Fredo.