The former One Direction singer was due to make his first U.K. live performance during the star-studded event at Wembley Stadium in London, following acts including Little Mix, Ariana Grande and Nick Jonas.

The entire show was due to end at an estimated 10pm local time, and Zayn was supposed to perform after U.K. singer Craig David, but the gap in between sets kept being delayed, until at 9.20pm an audio announcement was broadcast across the stadium informing fans Zayn wouldn't be playing.

Around the same time, Zayn took to social media to apologise to his fans and explain the reason behind his cancellation in a lengthy note.

"I flew into the UK last night to appear in my home country in front of my family, friends and most importantly, my UK fans,” he wrote. “Unfortunately, my anxiety that has haunted me throughout the last few months around live performances has gotten the better of me…with the magnitude of the event, I have suffered the worst anxiety of my career."

Zayn added how sorry he was to let his fans down after they had patiently waited to see him, but promised to make it up to them as soon as he could.

“I know those who suffer anxiety will understand and I hope those who don’t can empathize with my situation," he added.

According to concertgoers, the boos Zayn received following the announcement were "deafening" and many ticketholders left before the last act Tinie Tempah took to the stage to close the show.

This isn't the first time the 23-year-old Pillowtalk performer has been a last minute no-show in recent months, having pulled out of an appearance on British talk show The Graham Norton Show in January (16).

The following week, he cancelled an interview with BBC Radio One's Greg James moments before going on air, leaving fans who were lining the streets to catch a glimpse of the heartthrob devastated.