A man wanted over the abduction and rape of two women in London has been linked to a third attack.
Joseph McCann is wanted by detectives investigating the abduction of two women in Chingford and Edgware on 25 April.
Hertfordshire Constabulary said he was also linked to the rape of a 21-year-old in Watford on 21 April.
Officers believe McCann, who is also wanted on recall to prison, could be using disguises.
A £20,000 reward has been offered by the Metropolitan Police for information about his whereabouts that leads to his arrest and prosecution.
The BBC has been told he was originally jailed in 2008 for aggravated burglary after admitting breaking into the home of an 85-year-old man on 27 December 2007.
He was released on licence by the Parole Board in 2017 but had been recalled for breaching his licence.
During the attack in Watford, the victim was approached by a man holding a knife in Hagden Lane at about 03:30 BST.
She was forced into a blue Ford Mondeo and driven around the town for six hours before being raped.
The Hertfordshire force said the suspect had been identified after the attack was reported to them on 22 April.
"A significant amount of work was done to try and locate and arrest him, which proved unsuccessful," it said.
The next victim was abducted the following Friday in Chingford, north London, at about 00:30, with the third targeted at 12:15 in Edgware.
Both women, aged in their 20s, were raped before being driven to a hotel in Watford, where the suspect attempted to book a room but left when one was unavailable.
They both then escaped following a struggle in Osborne Road at about 14:30.
The Met said 33-year-old McCann, who has connections in Watford, Aylesbury and Ipswich, is known to use false names.
Det Ch Insp Katherine Goodwin said: "We would ask anyone with any information about McCann's whereabouts to contact us immediately.
"McCann is considered extremely dangerous and a risk to the public and we ask people not to approach him, but instead call 999."
McCann is described as white, with a muscular build, a bald head or shaved blond hair and a light-coloured short beard.
He is said to have a distinctive tattoo of the name "Bobbie" on his stomach.
A man, aged 33, has been arrested on suspicion of conspiracy to rape and released as inquiries continue.