Robert Man, 43, is wanted in his home country to complete a jail sentence for abusing seven youngsters during a three-year period.
Some of his victims were reportedly groomed after he landed a job driving children to a campsite run by a humanitarian charity.
Man is also wanted for possessing indecent images of children. His youngest victim was just nine.
He is currently on bail while appealing an extradition order made by a judge at Westminster Magistrates Court in London in July.
Man wears an electronic tag and is under a 7am to midday curfew at his home in Newport, South Wales, which allows him to do night shifts at an Amazon distribution centre in Bristol.
The retail giant confirmed Man was an employee but refused to say if they were aware of his criminal history. A spokesman said: “We are investigating.”
Alarmingly, Man’s rented room in Newport is just 150 yards from Stow Park Community Centre, which hosts weekly martial arts classes for kids as young as four, as well as children’s parties and clubs for youngsters with autism.
Willie Clason, secretary and trustee of Stow Park, said he did not recognise Man and that he has no connection with the centre.
“We have refugees coming here for food parcels, but they are thoroughly checked,” he said.
One neighbour with children, who did not wish to be named, said they no idea of Man’s past.
“It is terrible that someone wanted for such dreadful things against children is living so close by,” she protested. “We should have been told.”
Man has three years and three months left to serve of a five years and eight months sentence imposed by the County Court in Cluj in his absence in January 2020.
He was originally sentenced to 17 years and four months’ imprisonment after he made admissions to prosecutors in Romania in 2017.
However, Man was released months later after an appeal court ruled there had been errors during the original prosecution and that he “had not been fully entitled to exercise his right to defence.”
A judge set aside his conviction and ordered a retrial, where he was found guilty of eight sexual abuse charges, including five assaults, two counts of soliciting a minor for “sexual acts” and one child pornography offence.
By then he had fled to Britain after being given permission not to have to attend the hearings.
When he arrived in this country in 2019 he worked as delivery driver in Exeter, Devon, before securing his job with Amazon.
Man was arrested in March last year after handing himself in to police and was released on £3,000 bail while awaiting extradition proceedings.
Court documents reveal details of the offences Man is wanted for in Romania which involve seven different children between 2012 and 2015.
In one disturbing incident he simulated sex with a naked boy on his bed and repeatedly molested him.
An 11-year-old girl he assaulted said he caused her “discomfort and repulsion.”
Police in Romania said they found 20 image files of child pornography and he had tried to persuade some of his victims to take sexually explicit photographs of themselves.
Man told a reporter outside his Newport home he was not a sex offender: “It’s not true. The higher court in Romania decided “no” and they don’t find me guilty. I’m not ashamed.
“There was an abuse of process in Romania. Now the judge here over my extradition has it wrong.”
During his extradition proceedings, a medical expert said Man suffered from depression and was a potential suicide risk if he was sent back to Romania.
Ruling on Man’s removal, District Judge Richard Curtis said: “Having considered and dealt with all of the issues raised in this case in turn, I am satisfied no bar to extradition exists.”
The Crown Prosecution Service, which is representing the Romanian government in legal proceedings in Britain, confirmed Man had applied for permission to appeal his extradition.
A decision on whether the appeal will be granted has yet to be made.