Maggie May "was thin and had fleas"

The 21-year-old announced on her MySpace weblog that she had received a call from a man claiming to have bought Maggie May, an English bull terrier.

She wrote that friends had met the man and gave him a cash reward in return for her pet.

Allen said she was "overjoyed" but added that Maggie May was "very thin" so may have been "mistreated".

Allen, whose hits include Smile, said she had concerns after her friends were offered more puppies to buy, after Maggie May had been handed over.

"These people were obviously in the business of moving dogs. Now I feel guilty for having given these people money and contributing to their cruel business but I love that dog and felt I had no choice," she said.

She added that Maggie May had fleas which made her suspect she had been kept with other "maybe stolen" animals.

The star said the matter was now with the RSPCA and the police.

Lily Allen had a number one hit in 2006 with Smile

Allen added that she had been accused by some people of "neglecting her dog" which was "distressing and hurtful".

"People have been speculating that because Maggie was thin and had fleas she must have run away, Maggie was tied up and in her cage in the back of a van and could not have escaped, she was stolen," she said.

Maggie May was taken from her friend's van in Forest Gate, east London, on 28 December.

A spokesman for Dog Lost, a website that helps find missing canines, said there was a "huge" problem with such breeds being stolen in east London.

Allen pleaded for information about the theft on her MySpace page last week and also posted details of Maggie on the Dog Lost website.

The site's founder, Jane Hayes, said: "We think there are gangs operating in east London stealing dogs for organised dog fights.

"We also think they are being sold in pubs by people looking for quick money for drugs.