A cab driver convicted Friday of sex attacks on a dozen women is believed to be Britain’s most prolific sex attacker.

John Worboys was found guilty of 19 charges of drugging and sexually assaulting 12 female passengers. In one case he raped his victim. He was cleared of two counts of drugging women, but is thought to have attacked more than 500 during his 13-year career as a trusted licensed taxi driver.

A senior detective told The Times: "The truth is we’ll never know how many women Worboys attacked but it could easily be hundreds and hundreds."

Worboys, dressed in a grey suit and tie, put his face in his hands and shook his head as he stood in the dock. As the guilty verdict for rape was read out he said: "Oh my God," and wiped away tears before Justice Penry-Davey told him to expect a "very substantial term of imprisonment." He then looked at a friend in the public gallery and shook his head in disbelief.

The former porn actor and stripper, who performed under the name of Terry the Minder at gay venues, was arrested by police in the summer of 2007 but was freed to attack scores more women, at least 30 while he was on bail.

Senior officers have discovered that 12 women had gone to the Metropolitan Police before Worboys was charged to complain about a black cab driver trying to drug, sexually assault or generally pester them, but their claims were never linked.

Since his arrest, 75 more women have come forward to tell police they believe that Worboys attacked them too, including four from Dorset, where he had an apartment and would sometimes take his taxi.

He was charged with attacking 14 women in a 16-month period after looking for potential victims coming out of nightclubs and bars, Croydon Crown court was told.

Click here to read more on this story from The Times of London.