A man suspected of abducting and raping three women is being hidden by a friend or family member, police believe.
Joseph McCann, 34, is alleged to have attacked three women in north London and Watford last week.
Det Ch Insp Katherine Goodwin said there was no evidence Mr McCann had left the country and urged anybody helping him to “please call us”.
The Ministry of Justice is carrying out a review into whether Mr McCann had been released from jail by mistake.
Speaking outside of New Scotland Yard, Det Ch Insp Goodwin said whoever is hiding the 34-year-old “possibly isn’t aware of the full nature of his crimes”.
She said it appeared the women had been “selected randomly”, then abducted “in an incredibly violent manner”.
“Please consider if your mother, sister, daughter, niece or friend had experienced such an awful attack and put yourselves in the shoes of their family,” the detective said.
The Met has offered a £20,000 reward for information leading to Mr McCann’s arrest and prosecution.
The first attack took place in Watford on 21 April where a woman was approached by a man armed with a knife who drove her around in a car for six hours then raped her.
On 25 April, two women were abducted in Chingford and Edgware within the space of 12 hours.
They were both raped then driven to a hotel in Watford where their attacker was unable to book a room. Soon after they managed to escape during a struggle.
The force has described Mr McCann as a “violent individual who is a risk to women and poses a threat to children” and warned people against approaching him.
A 63-year-old woman from Aylesbury was arrested on Tuesday on suspicion of intimidation of witnesses in connection with one of the attacks. She has been released on bail.
A 33-year-old man arrested on Sunday on suspicion of conspiracy to rape has been released under investigation.