Police understood to be investigating new 'historical sexual assault' allegation against John Worboys
Video report by ITV News Correspondent Juliet Bremner
A fresh allegation of sexual assault has been made against convicted rapist John Worboys, ITV News understands.
A Metropolitan Police statement said an investigation into a "non-recent sexual assault" reported this month is underway.
But it said that no arrests have taken place.
The statement said:
The fresh allegation comes as Worboys was moved to a London jail ahead of his release just nine years after he was jailed.
The 60-year-old was jailed indefinitely in 2009, with a minimum term of eight years, for drugging and sexually assaulting women passengers.
Worboys was convicted of 19 offences against 12 victims but has been linked to more than 100 complaints in total.
After the Parole Board's decision was revealed, there were calls for him to be located away from Greater London to reassure terrified victims.
Last week, the government confirmed it would not challenge the Parole Board's decision to release Worboys prompting lawyers for the victims to launch their legal challenge independently.