Citing scientific research which it had commissioned, it said an estimated two kilogrammes of cocaine, or 80,000 lines, spill into the river every day after it has passed through users' bodies and sewage treatment plants.

It extrapolated that 150,000 lines of the illegal drug are snorted in the British capital every day, or 15 times higher than the official figure given by the Home Office.

"Because of the long-term complications of cocaine use, we are looking at a healthcare time bomb," clinical toxologist John Henry was quoted as saying.

Cocaine use has been in the headlines in Britain after fuzzy images of supermodel Kate Moss apparently enjoying some lines in a London recording studio were published in a tabloid newspaper.

She soon went into detox after losing some of her most lucrative contracts, but is already making a comeback, appearing Sunday on the front page of several newspapers -- including the Sunday Telegraph.