Zayn Malik
Zayn Malik was released from One Direction's world tour in 2015 due to stress, and left the band afterwards Kevin Winter/ Getty

One Direction fans will be excited to know that Zayn Malik is said to be writing a tell-all book, which is expected to document details about the five years he spent touring the world with One Direction, his four-year relationship with Little Mix star Perrie Edwards, and his 10-month on-off liaison with supermodel Gigi Hadid.

"This book is going to be explosive and Simon [Cowell] will be furious with Zayn and may even try to stop it coming out. But Zayn is determined to reveal the secrets behind the clean image that was always so fiercely protected by the band's publicity machine," a source told Daily Mail.

Simon Cowell, 56, signed One Direction after the 2012 season of X Factor. But Malik sensationally quit the band in March 2015, after being excused from the band's world tour due to stress.

At the time, the 23-year-old singer told MTV: "I did try to do something that I wasn't happy doing for a while, for the sake of maybe other people's happiness — and that was mainly the fans."

"And I only ever tried to do it for the fans, and it was only ever for them," he explained. "And, basically, I'm only upset I feel like I may have let them down in some sort of way.

"That's the main thing that I don't want to happen. It's not that I've turned my back on them or anything, it's just that I just can't do that anymore because it's not real to me."

At the time there were rumours that Malik was unhappy with the songs One Direction was asked to play, which he confirmed to MTV: "It was generic as f**k," the performer said. "That's not music I would listen to."

Soon after leaving One Direction, Malik broke up with his fiance, Little Mix star Perrie Edwards. The pair had been together for more than four years and were also engaged. He was quickly linked with supermodel Gigi Hadid. In July 2016, a source told The Sun that Malik and Gigi Hadid had moved in together.