Rock star Pete Doherty walked free from Wormwood Scrubs Prison in West London at around 7:10 am yesterday, according to media reports.

The singer, who has fought a long and public battle with drug addiction, served just 29 days of a 14-week sentence for breaching his probation.

Dressed in a suit and tie, he told the waiting media he was pleased to be out and was looking forward to having a rum and coke and spending some time with his pet cats, showing the media a certificate confirming he had passed a drugs test while serving his sentence.

His release comes despite claims Doherty smoked heroin behind bars even though he was taking the heroin substitute methadone.

The singer was jailed last month by District Judge Davinder Lachhar at West London Magistrates' Court after Doherty was handed a four-month suspended jail sentence in October for possessing crack cocaine, heroin, ketamine and cannabis.

His supervision order required him to make regular visits to court for progress reports, as well as take part in a drug rehabilitation programme.

Doherty has been serving his sentence in segregation after claims that other prisoners plotted to attack him.

In September 2003, Doherty was given a six-month jail sentence after admitting burgling the home of his former Libertines bandmate Carl Barat.

His release means Doherty is free to play on the Park Stage at the Glastonbury Festival late next month.