Amy Winehouse parties until 4.30am after checking herself out of clinic

Amy Winehouse was back in her old stomping ground last night after checking herself out of a London clinic.

The troubled star marked her release from hospital by partying until 4.30am amid fears she'll resume her bad habits.

The Rehab singer visited live music venue The Monarch and stopped in at a kebab shop before returning home to carrying on the party with friends.

Back on the town: Amy Winehouse was out in Camden until 4.30am this morning after checking herself out of hospital

Amy insisted on leaving the facility yesterday after a disastrous appearance at Glastonbury, during which she allegedly lashed out at a fan.

A source is quoted in The Sun as saying: 'We feared a taste of the outside would remind her what she’s missing and it would be hard to get her back into life at the clinic. That’s exactly what’s happened.”

'Sunday was like she was on a terrible comedown from the whole thing. She kicked off and threw all her toys out the pram.

Late night: The troubled singer was back roaming around her old stomping ground

'She told Mitch : "I’m climbing the walls in here. I need to get out". She said if he didn’t help her get out, she’d walk out.

'He realised he had to let her leave, otherwise he’d have no control over where she goes and what she gets up to.'

Lashing out: Amy was accused of elbowing a fan after performing at Glastonbury over the weekend

Amy was admitted to hospital two weeks ago after she fainted at home.

She was later diagnosed with early stages of emphysema.

A spokesman for Amy confirmed she had left the clinic and would be treated as an outpatient.

Meanwhile, Amy's husband Blake Fielder-Civil has been accused of writing a series of explicit love letters to another prison inmate, Melissa Goldstone, who is serving time on drug charges.

One extract, printed in The Sun, reads, 'I've told Amy about you and read a bit of one of your letters. I don't want her to know about all the personal things I've written to you.

'Only a few weeks left, baby, we'll have a night on our own in a hotel somewhere, blazing and drinking and some twisted, hot, sexy things.'

Blake is in London’s Pentonville jail awaiting sentence for assault and conspiracy to pervert the course of justice.