Image copyright Met Police

A suspected triple rapist being hunted by police may have been mistakenly released from prison, it has emerged.

Joseph McCann, 34, is alleged to have abducted and raped three women in north London and Watford last week.

He was not - but should have been - referred to the Parole Board before he was released from prison in February, while halfway through serving a sentence for burglary.

The Ministry of Justice said an "urgent review" of the case was under way.

McCann was jailed in 2008 for aggravated burglary after admitting breaking into the home of an 85-year-old man.

He was given an Indeterminate Sentence for Public Protection (IPP) with a minimum term, or tariff, of two-and-a-half years.

This meant the Parole Board had to decide if it was safe to release him once his tariff expired in 2010.

In 2017 he was released on licence, which meant he could be sent back to jail if he reoffended or breached his parole conditions.

Later that year, while on licence, McCann was arrested and charged with a further burglary.

He was given a three-year jail sentence.

McCann's case should have been referred to the board before he was released but in February this year he was dealt with as a "determinate sentence" prisoner.

This meant he was automatically released 18 months into his sentence.

A £20,000 reward has been offered by the Metropolitan Police for information about McCann's whereabouts that leads to his arrest and prosecution.

Detectives described McCann as "extremely dangerous" and said people should call 999 if they saw him.

He is described as white, with a muscular build, a bald head or shaved blond hair, a light-coloured short beard, and the name "Bobbie" tattooed on his stomach.