An investigation has been launched against John Worboy's by the Metropolitan Police after a new allegation was made last month.
Worboy's, who's imminent release has caused uproar, is being investigated regarding an incident which allegedly took place in 1997.
Scotland Yard said in a statement: "The Metropolitan Police Service is investigating an allegation of non-recent sexual assault which was reported to police in January 2018. The incident is reported to have taken place in 1997.
"Enquiries by officers from the Child Abuse and Sexual Offences Command are ongoing."