Simon Cowell - Cowell Thought Ailing Cole Was Hungover

SIMON COWELL presumed his THE X FACTOR co-star CHERYL COLE was suffering from a hangover shortly before she collapsed with malaria.

The Girls Aloud beauty shocked her entourage when she fainted during a photoshoot in July (10) and she was later diagnosed with the mosquito-borne disease, which left her in intensive care.

Cole picked up the illness during a trip to Africa in June (10), but Cowell - the star's boss on the hit U.K. talent show - was convinced she was suffering the after effects from a boozy birthday bash.

He tells Britain's The Sun, "We didn't know what was going on. I remember saying funnily enough that she had gone to Africa for a trip and had come back for filming and I thought she was a bit off-colour, but more personality than physically.

"And then the day it kicked off we actually thought she had a hangover, so we were winding her up all day, and she was sleeping it off or whatever.

"And then of course we realised that it was serious a couple of days later. I got the call from her manager who told me just how serious this really was.

"In that situation you are not even thinking about the show at that point. You are just thinking, 'I hope she is going to be OK.'

"I didn't know much about it, but apparently it was a serious strain. We were very, very worried about her, she was seriously ill."