Could this oddly-shaped cigarette be the real reason Lily Allen is 'exhausted'?

The 'Smile' singer was photographed at London's world famous Notting Hill Carnival in possession of a large hand-rolled cigarette.

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Silly Allen: Lily was seen at the Notting Hill Carnival enjoying a large hand-rolled cigarette

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The singer made the most of the bank holiday fun and was reportedly drinking heavily

Glassy-eyed Lily huddled among her friends as she smoked the unusually large roll-up. It was almost as if she didn't want to be seen.

Shortly after, Lily - who had been seen drinking heavily for most of the day - reportedly passed out on the pavement outside trendy pub The Cow and had to be helped to her feet by staff from nearby restaurant Rosa's Dining Room.

The 22-year-old singer whose hits include LDN and Smile recently cried off four major European festival performances, even posting a doctor's note on her MySpace page, to inform disappointed fans she was suffering from "sinusitis and strep throat".

Allen told fans: "Before anyone starts trying to accuse me of neglecting my fans I want to apologise and say how sorry I am, but I can't risk causing any permanent damage." She was advised to take a couple of weeks off.

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Lily recently cancelled four European festival appearances due to illness but she seems to have perked up somewhat

But that clearly didn't stop her from enjoying herself to the fullest at the Caribbean festival.

A source told The Sun: "She was really getting into the spirit of the occasion when she stumbled and didn't get back up.

"People were crowding around and taking pictures of her until the staff came to her rescue. They took her inside the restaurant to stop everyone staring at her."

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The singer got into an onstage altercation with singer Bobby Kray which ended when he poured Guiness over her

After drinking several pints of water and strong coffee to sober up, the pop star was put by staff in a taxi which took her to her north London home.

Earlier in the day, Lily suffered further embarrassment when she had a pint of Guinness poured over her head.

The diminutive star jumped on stage during a performance by reggae star Bobby Kray and pushed him off stage so she could sing herself.

Bobby retaliated by throwing the stout drink over her, receiving cheers from the crowd for his efforts, leaving Lily to sulk at the side of the stage.