Paul Higgins has quit as One Direction's tour manager after a suspected fall-out with boyband member Zayn Malik.

Mirror reports that Higgins flew back home to UK while One Direction was promoting their latest album, "Four," in the United States. Insiders claim that Higgins had a feud with Malik, and that it was also the reason why the singer was absent from the boyband's appearance on the "Today" show a few days ago. Other members of the band claimed that Malik's absence was due to a stomach bug, but "Today" show host Matt Lauer brought about rumors of substance abuse during the interview.

Inquisitr suggested that "Higgins got frustrated with Zayn because he knew that the singer wasn't really sick." The singer's band mates also revealed that he has a bad habit of "[disappearing] for days without letting anyone know where he is."

"There have been issues behind the scenes for a while, and they've finally come to a head leading to Paul's relationship with the band coming to an end," the source revealed, as quoted by Mirror.

Higgins has worked with the band since 2010 and became "one of their closest confidants and a major part of their touring operation," Mirror noted. The group -- composed of Malik, Harry Styles, Liam Tomlinson, Niall Horan, and Louis Tomlinson -- also fondly call Higgins "Daddy," Mirror added.

According to the news outlet, the insider also stated that Higgins is "solid as a rock" and "totally dependable." All five members of One Direction attended Higgins' wedding in Ireland and even made a video for the celebration. The video went viral online and gained two million views worldwide.

"In many ways he [Higgins] has completely run the show while they've been on tour -- they even call him Daddy. He became a friend as well as a key part of their management set-up. He's always been at the heart of the One Direction team, and it's hard to think of them going on tour without him there," the source stated, as quoted by Mirror.

Zayn Leaving 1D?

There have been rumors circulating that Malik plans to leave the band. OK! reports that the singer is tired of fame and wants to spend more time with fiancée Perrie Edwards.

"Zayn is fed up with the whole fame thing. He loves singing and his fans but he just wants a quiet life now. He has become increasingly disappointed with with the little amount of time he can spend with Perrie," OK! reports, quoting the paper Sunday People. "Zayn appreciates how lucky he is but life is about family for him and he is seeing too little of his loved ones."