A One direction “Fixer” prepares to uncover the boy band’s darkest secrets in a tell-all book.

The insider – who was at the heart of the group for a decade – has compiled a diary of his time on the streets, chronicling the worst excesses of drink, drugs and groupies. RadarOnline can reveal exclusively.

As fans continue to mourn the death of a band member Liam PayneA celebrity confidant has photos, recordings and documents to back up what could be the most explosive book about the music industry in decades, according to a well-informed source.

The high-ranking mole revealed: “This person knows his stuff. He was the band's go-to guy when things like fights with girls, jealous boyfriends and hotel managers complaining about broken rooms and unpaid bills needed to be sorted out.”

“He was the guy who sorted out the drinks, the drugs and the groupies for the after-show parties and looked the other way when things got out of hand.

“Besides, he didn’t look away. He wrote everything down and recorded the events: the good, the bad and especially the ugly.”

The tome will also detail how the band's bosses were signed by the music guru Simon Cowell after his appearance on the British version of the talent show The X Factor ensured that the boys produced hits and live performances at all costs.

The source added: “There was a brutal and cynical money-making regime that backed the boys.” 1Ds Bury secrets and keep the band on tour at all costs.

“Liam Payne died haunted by the horrific reality of the boy band business and his group member Zayn Malik He also found it very difficult to bear the price of fame and so he left the band before it dealt an even more serious blow to his mental health.

Together with Nicole ScherzingerCowell selected the boys from the groups of aspiring singers and supervised the band throughout the competition on the TV show.

After finishing third, the music mogul signed them to his label Syco Records, where they sold over 70 million records.

After Payne's shock death at the age of 31 Buenos AiresArgentina, there was a wave of grief throughout the music industry and beyond.