Zayn Malik walked off stage after falling ill during a gig.
The 22-year-old singer exited just three songs into the performance in Perth, Australia, last night with band mate Niall Horan later informing the crowd he was too sick to return.
A spokesperson for the group - which also includes Harry Styles, Louis Tomlinson and Liam Payne - said: "Zayn was taken ill during the show but it's nothing serious.
"He wasn't feeling that great beforehand but he tried to get through the performance as well as he could.
"Everyone is hoping he'll be well enough for their next gig."
It isn't the first time the 'Night Changes' hitmaker has pulled out of his One Direction duties in recent months.
The star was also missing during their appearance on America's 'The Today Show,' during a promo tour to the US last November, and was forced to defend himself over false drug use claims made by host Matt Lauer following his no-show.
Zayn told The Sun newspaper at the time: "I was really ill at the weekend, that's why I couldn't fly to America. I was gutted to have to miss album release day."
He added he was "really angry and upset" by the claims.
It is hoped the singer will soon recover as the band are only on the seventh date of their two-week Australian tour and are set to fly to Japan for more performances next week.