Cabbie John Worboys is believed to be the UK's most prolific sex offender after it has emerged he may have attacked at least 102 women.
Worboys, 53, was jailed indefinitely in April 2009 for drugging and sexually assaulting women passengers.
At the time, detectives linked him to at least 85 crimes.
But Scotland Yard has said that a number of women had come forward since he had been behind bars, and that his alleged victims now number more than 100.
Around 19 women have made allegations against him since his conviction, police said. And it is thought there may be still more victims who have not come forward.
Not all the women claimed the former stripper and adult film star had raped them, but all accused him of sexually motivated offences. The attacks are believed to have been carried out over a period of about five years, between 2002 and 2007.
A Metropolitan Police spokesman said: "There is a high possibility there are more victims out there. The difficulty is that a large number of the women do not know whether they were raped or not. The only person who knows is Worboys himself. We hope he might consider telling us in the future what went on."
In March 2009 Worboys was found guilty at Croydon Crown Court in south London of assaulting 12 women during an 18-month reign of terror in the capital. The cabbie offered them Champagne spiked with powerful sedatives to celebrate a fictional lottery win, backed up with a carrier bag stuffed full of cash.
Worboys was told he must serve a minimum of eight years in prison for the attacks and would not be released until parole officials were convinced he did not pose a threat to women.