Robbie Williams once gorged on $32 (£28) worth of chocolate while sleeping

He said: "Because of Ambien, I ate $32 worth of chocolate, asleep. Completely asleep." The 47-year-old singer - who suffers from insomnia and previously battled with drug and alcohol addictions - revealed his sleeping disorder heightened during his 2007 'Close Encounters' tour when he would eat "like a monk" in the day, but finish off the mini bar at night.

He continued: "All the way through that tour I was living like a monk food-wise during the day, sort of my body as a temple.

"But then at night, I'd be taking these Ambien and then I would be eating the mini bar. I'd be eating the menu - don't remember any of it."

The 'Let Me Entertain You' hitmaker - who has four children with wife Ayda Field - also gave his security staff a fright by sleeptalking to them while stark naked.

Appearing on 'The Past Weekend' podcast, he said: "My security on tour, they'd have the Ambien.

"And I'd be like, 'Can I have them?' So, they'd give me the Ambien. And then I'd go next door, and then I'd have my Ambien and I'd fall asleep on the Ambien.

"And then I would get up completely naked, go through the security room and have a conversation with them as lucidly as this but completely naked and asleep.

"And then I'd wake up the next morning and I'd say, 'I didn't do it, did I?' And then this look in their eyes would just be like, 'Yes, you did, you did do it.'"