If they are not launching themselves at you in drug-fuelled desperation, their bloodshot eyes are searching for their next fix, pink paws scrabbling in the ground. Sometimes they seize upon a rock of crack hidden in front gardens, and scarper to feed their addiction.

Squirrels in south London could have become addicted to crack cocaine, say residents of Brixton, who suggest the rodents have dug up drugs buried by dealers or nibbled residues of crack on pipes and vials discarded by addicts.

According to internet legend, crack squirrels have terrorised residents in New York and Washington. But is the Brixton crack squirrel real or an urban myth? The Guardian began its search for the freebasing fiend near the local cinema. "They used to hang out in the little park in front of the Ritzy, twitching ... dancing to music only they could hear and generally creating a malevolent ambience," Londoner Rik Abel wrote in his blog. Ritzy regulars were less sure. "I've never seen one," said a staff member. "But there might be crack foxes around too."

On Brixton Hill, Bim is not surprised by the spectre of the Brixton crack squirrel. "I've only been released from prison today but I've heard about the squirrels. They are scoffing all the crack, more stoned than me. Have you ever seen cats with hash? Cats always go for hash."

There is no sign of a squirrel half-crazed on Class As along Coldharbour Lane or Rush Common - but, finally, a possible sighting. "I've just seen one jump down from an old sunflower by the Seventh Day Adventist church," said Reg Throssell. "I locked eyes with it and it stared back at me really confidently. It was scavenging and it looked scrawny."

But Brixton crack squirrels need not worry about the police yet. "I've no knowledge of that at all," said a Scotland Yard spokesman, firmly.