An urgent review has been launched over fears that an “extremely dangerous” rape suspect currently being hunted by police may have been wrongly released from prison. Joseph McCann, 34, is wanted over the abduction of two women in their 20s who were separately snatched off the streets in north London last Thursday.

He is also suspected of holding a 21-year-old woman at knifepoint in Watford in the early hours of 21 April and raping her, Hertfordshire police said.

It is understood that McCann was released on lifelong licence in February 2017 after serving 10 years of a now scrapped indeterminate sentence for aggravated burglary.

He was jailed again the same year for theft and burglary but is believed to have been mistakenly released automatically halfway through his three-year sentence. It should have been up to a parole board to decide whether he was released or stayed behind bars, because he was still subject to licence.

A Ministry of Justice spokesman said: “We have commissioned an urgent review into what happened in this case.”

Scotland Yard has offered a reward of up to £20,000 for information leading to McCann’s arrest and prosecution. Police have warned that he is “extremely dangerous”, known to use false names, and may be using a disguise.

He is described as being muscular, about 5ft 10in, and having a “distinctive” tattoo of the name “bobbie” on his stomach. He is said to have blue eyes, a bald head or shaved blond hair with a light-coloured beard, and a “slight” Irish accent. Officers said he had recently gone by the name of Joel and has links to Watford, Aylesbury in Buckinghamshire and Ipswich.

The women abducted in London were raped after being snatched by a man in a silver or grey Ford S-Max with false registration plates. The first woman was abducted at about 12.30am on Thursday from a street in Chingford. The second was seized around 12 hours later at 12.15pm from a street in Edgware.

They were driven to a hotel where the man attempted to book a room at around 1pm. They left when this was unavailable. The women managed to escape in Osborne Road, Watford, at about 2.30pm. They were both traumatised by the ordeal and have been receiving support from specialist officers, police said.

The incident is being linked to another attack earlier in the week that is being investigated by Hertfordshire police. The force said a woman was approached at around 3.30am on April 21 in Hagden Lane, Watford, driven around for six hours in a blue Ford Mondeo, and then raped. The incident was reported to police the following day.

On Tuesday a 63-year-old woman from Aylesbury was arrested on suspicion of intimidation of witnesses in connection with the attack and released on bail.

A 33-year-old man arrested on Sunday on suspicion of conspiracy to rape has been released under investigation.