The 54-year-old attacker, who critics believe was allowed to remain free for so long because of police blunders, is known as the "black cab rapist," The Guardian reported.
"There is a high possibility there are more victims out there," the BBC and Guardian quote a police spokesman as saying. "The difficulty is that a large number of the women do not know whether they were raped or not."
Worboys attacked his female victims at night, offering them champagne laced with sedatives and sleeping pills, according to The Guardian. He fooled young professionals into having the drinks by saying he had just won the lottery.
An investigation found that Worboys was able to avoid conviction for so long because police did not take his victims seriously, and tended to doubt that a driver of one of London's iconic black sedan taxis would be capable of such attacks, The Guardian reported.
"The victim cannot remember anything past getting in the cab," one detective wrote in his report dealing with a 2007 victim. "It would seem unlikely that a cab driver would have alcohol in his vehicle, let alone drug substances."
Worboys will serve a minimum of 8 years in prison.