Pete Doherty treated fans to an impromptu performance on a recent shopping trip.

The Babyshambles singer was at Music Man music store in Reading when he entertained other shoppers with a few of his hits – before being prematurely halted by a broken guitar string.

Pete then reserved a £150 guitar and vowed to return later and pay the owner, Peter Sirrell, for the one he had broken.

Mr Sirrell told the Reading Evening Post: "I thought he was a really nice guy and he was happy to chat, but he got a little bit uncomfortable when a crowd gathered in here. He played a song about a pimp or something like that."

Speaking to the newspaper, Kate Moss's ex revealed that he was in town to play a secret gig but would not reveal any more details.

The star, whose personal battles with drink and drugs have been well-documented in the press, is rumoured to be taking part in a new Channel 4 documentary about the effects of heroin.

According to the Middleton Guardian, he will lodge with a family in Sheffield's Langley estate to see how addiction impacts upon their lives.

He will also attempt to engage youngsters in music therapy in a bid to help them kick the habit.

20/03/2008 10:58:26