Joseph McCann, the suspect in three rapes who was arrested in the early hours of Monday, is being questioned over attacks on nine further victims, aged between 11 and 71, in the previous 24 hours.

Police confirmed the suspect captured in the Cheshire countryside was McCann, wanted over the three recent attacks in south-east England, and revealed he was being investigated for a series of “grotesque and horrifying” rapes, sexual assaults and abductions over 10 hours on Sunday across the north-west.

In total, he is being investigated for seven incidents, with 12 potential victims so far identified, including young women, teenagers of both sexes, a young boy and a female pensioner.

McCann was spotted on Sunday evening after the abduction of two 14-year-old girls in Congleton, Cheshire, who escaped unharmed. There was a standoff with police and he was arrested at about 3am.

Police had been hunting McCann after he was named on 25 April in connection with the abduction and rape of a 21-year-old woman at knifepoint in Watford on 21 April. The same day he was named, two women in their 20s in north London were abducted and raped, before being taken to Watford, where they escaped.

On Monday, police detailed the further attacks they were now investigating in connection with McCann. On Sunday at about 8am, a woman in her 30s was “falsely imprisoned at a location” in Haslingden, Lancashire, and a teenage girl and an 11-year-old boy were raped in the same incident.

Just over five hours later, at about 1.30pm, a woman aged 71 was abducted and raped in Bury, Greater Manchester. Two hours later in Heywood, Greater Manchester, two 13-year-old boys and a 13-year-old girl were abducted, and the girl was sexually assaulted.

The same day at about 6.30pm, two 14-year-old girls were forced into a car in the market town of Congleton, Cheshire. They were not sexually assaulted, police said. A black Fiat Punto crashed into another car, and the two teenagers were found inside.

Cheshire police’s chief inspector, Gareth Wrigley, said: “The two girls abducted were both located safe and well. However, they are extremely distressed as a result of their ordeal and are currently being supported by specially trained officers.

An inquiry has been launched by the Ministry of Justice to examine if McCann was released from prison by mistake when he was freed partway through a sentence on licence for an aggravated burglary.

The investigation into McCann is being led by the Metropolitan police, which will work with all the other forces in the areas where the incidents occurred.

Det Ch Insp Katherine Goodwin from the Met’s homicide and major crime command confirmed McCann was being investigated for offences committed in Cheshire, Manchester and Lancashire, in addition to London and Hertfordshire.

“These attacks were grotesque and horrifying. These victims are now being supported by specialist officers. Further details concerning specific offences will become clearer in due course,” she said.

“I would urge any other victims to come forward. We also need to hear from anyone who has been approached or been in contact with McCann between April and May.”

The Met commander Simon Rose said: “I think we’re exceptionally relieved that he’s in custody and exceptionally grateful for the help and support we’ve had of so many members of the public in all the calls.

“These were and they are a grotesque and appalling series of offences that are thankfully exceptionally rare, so it’s extremely important that he is in custody.”

Rose said it was impossible to know whether there are further victims and urged people who have been in contact with McCann since his release from prison to come forward.

A Met spokesperson could not say if anyone else was wanted on suspicion of helping McCann escape justice since he was named by police on 25 April. Last week, the force said: “Our enquiries strongly indicate that McCann is being hidden by someone who knows him.”

A £20,000 reward had been offered for McCann’s capture.