Zayn Malik was ''ordered'' to take a break from the One Direction tour.

The 22-year-old singer left the band's On The Road Again world tour to fly home to the United Kingdom after being signed off for stress but it was reportedly the decision of the ''higher-ups''.

A source said: ''The higher-ups ordered Zayn to take a break because there are concerns for his well-being.

''Zayn's management is livid right now, but they are also very sympathetic to his situation. He is in bad shape, which is the real reason he went home to London.''

And those close to the band are fearing it may be the ''beginning of the end'' for the boy band as Zayn has been ''separating himself'' from the others - Harry Styles, Liam Payne, Niall Horan and Louis Tomlinson - for ''quite some time''.

An insider told RadarOnline.com: ''A lot of people in their camp fears that this is the beginning of the end for One Direction...

''Zayn has been separating himself for the guys for quite some time now. He loves the guys but doesn't love everything that comes along with the band.''

The source also claimed it was the ''last straw'' for Zayn when speculation spread about his relationship with Little Mix star Perrie Edwards after he was photographed appearing to be holding hands with a fan whilst partying in Phuket, Thailand.