An 85-year-old former Catholic priest today admitted sexually assaulting seven children, including altar boys, after spending more than 20 years on the run in Spain.
Francis Paul Cullen was extradited back to the UK last year to face the charges after being traced to Tenerife.
The Catholic Church and its safeguarding board helped police to trace Cullen who was found to have attended mass at a church in Playa de las Americas every Sunday.
Today Dublin-born Cullen, looking frail in the dock, pleaded guilty to 21 charges at Derby Crown Court committed between 1957 and 1991.
The offences, on children aged between six and 16, took place while Cullen was a practising priest in Mackworth, Derbyshire and later Buxton, Derbyshire, and Hyson Green, Nottinghamshire.
Cullen pleaded guilty to 15 counts of indecent assault, five of indecency with a child and one of attempted buggery.
Judge Jonathan Gosling told Cullen that a "very substantial" custodial sentence was inevitable.
Prosecutor Sarah Knight told the court Cullen was extradited from Tenerife last year on a European arrest warrant containing a series of charges of sexual abuse.
She said further complainants had come forward and, due to the European arrest warrant, they had needed to seek the permission of the Spanish authorities to charge Cullen with further offences.
But Cullen agreed to the further charges, meaning they no longer needed to seek the authorities' approval, the prosecutor told the court.
Following today's guilty verdicts, the judge adjourned sentencing until March 24 at Derby Crown Court and Cullen was remanded into custody.
Speaking after today's verdict, Detective Constable Matt Goodwin, from Derbyshire Police, said: "We are very pleased with the guilty verdict today. This will save his victims from having to attend the court and provide evidence at a trial.
"I would very much like to thank the victims of this case for coming forward to the police.
"It is due to them coming forward that Cullen had today pleaded guilty to the offences. Without their help and support, this man would still not have been brought to justice."
Derbyshire Police said the crimes were committed against five altar boys and two young girls whose relatives had connections with the Catholic Church.
Four altar boys were abused while Cullen practised in Mackworth, Derbyshire, between the 1950s and 1970s.
In the 1980s, he abused two girls after he moved to work in Buxton, Derbyshire, and then went on to abuse another altar boy between 1989 and 1991 after he moved to Nottinghamshire.
Derbyshire Police said Cullen fled to Tenerife in 1991 after facing charges brought by Nottinghamshire Police.
Cullen was charged with three counts of sexual assault against three altar boys at Nottingham Magistrates' Court in October 1991.
While on bail awaiting his next court appearance, Cullen, then in his 60s, fled to Tenerife where he remained for the next 22 years.
A warrant was issued for his arrest but this was withdrawn in 2000.
In a statement issued today, Nottinghamshire Police said: "In September 1991, Nottinghamshire Police charged Francis Paul Cullen with sexual offences. Cullen appeared at court in October 1991 and was bailed.
"He failed to return to court and the court issued a warrant for his arrest. In 2000, the court withdrew the warrant which effectively meant he was no longer wanted."
Cullen was finally tracked down to Tenerife following a lengthy investigation by Derbyshire Police.
Derbyshire Police launched their investigation in 2005 after an altar boy who had been abused in the 1960s came forward.
Inquiries, including the use of Interpol, failed to track down Father Cullen and the case was closed pending further information.
It was reopened a year later when a female complainant came forward to the force who had been abused by Cullen in Buxton in the 1980s. The investigation was closed again when Cullen could not be traced.
The breakthrough came five years later when Cullen was traced to Tenerife in 2012 with the help of the Catholic Church and their safeguarding board, Derbyshire Police said.
Police were told Cullen had attended Sunday mass at the same church in Playa de las Americas for 20 years.
He was finally detained on a European Arrest Warrant on the island on August 20 last year by officers from the Serious Organised Crime Agency (Soca).
Cullen was extradited back to the UK and appeared at court charged with offences against three complainants on the warrant, Derbyshire Police said.
The complainants, who were all altar boys, included the victim who had made the original report to Derbyshire Police in 2005, a man who had been abused in the 1950s, and a Nottinghamshire victim from the previous indictment in 1991.
The force also looked at the two other charges from Nottinghamshire in 1991. The CPS found there was not enough evidence to proceed with allegations made by the second complainant and the third complainant could not be traced.
Following publicity from the court hearing, further victims came to light, Derbyshire Police said.
Cullen was charged with further offences against four more victims - two more males and two females.
Today the court heard Cullen abused the first victim between the ages of eight and 12, from 1957 to 1961.
The most recent victim was an 11-year-old boy between 1989 and 1991.
Detective Constable Matt Goodwin said the Catholic Church had been very supportive of the investigation and that the safeguarding board has been "instrumental" in helping to track Cullen down.
Dc Goodwin said: "The first real breakthrough in the investigation was in 2012 when with a great amount of co-operation from the Catholic Safeguarding Board we were able to locate Father Cullen in Tenerife.
"That was instrumental in Derbyshire then being able to apply for the European Arrest Warrant which we eventually brought him back to this country on."
Referring to the victims of Cullen's abuse, the officer said: " It has been a long, protracted inquiry. They've had to live with what Father Cullen has done against them for many, many years but I hope today can offer some degree of finalisation for each one of those victims.
"I think for a number of the complainants I'd go as far as to say that this has probably ruled their lives since the abuse took place."
The officer also added that he believed there were more victims of Cullen's abuse who had not yet come forward.
"The consistent thing throughout all of the victims was that they came into contact with Father Cullen through the Catholic Church and that was his way in.
"The span of offending ranges from 1957 up until around 1991. I think it would be inconceivable that there are no other victims of Father Cullen's sexual abuse.
"My message on behalf of Derbyshire Police is if there are any other people who would like to talk to the force in light of this latest conviction then please come forward.
"Any allegations will be fully investigation and then the appropriate action can be sought."
Cullen was ordained on May 30 1953 and worked as a parish priest of Christ the King, in Mackworth, Derby, between 1960 and 1978. He then moved to St Anne's Church, Buxton, in 1978 where he remained until 1987. A year later he moved to St Mary's Church in Hyson Green, Nottingham, where he remained until 1991.
He had worked at churches in Scunthorpe, Leicester and Alfreton, Derbyshire, before moving to Mackworth, the Diocese of Nottingham said.
Following Cullen's appearance at Derby Crown Court today, Father Andrew Cole, spokesman for the Diocese of Nottingham, said: "The Diocese of Nottingham, which covers the areas where Francis Paul Cullen worked as a priest, is pleased that he has taken responsibility for his terrible crimes and pleaded guilty to the 21 offences with which he was charged.
"We have been working closely with the police throughout the preparation of this case, both before and after Cullen's arrest in Spain and return to the United Kingdom, have encouraged them to bring him to justice and are grateful to them.
"I would like to offer our sympathy to those who have been affected by this tragedy in any way and assure them that we will do whatever we can to support them. I also wish to thank Cullen's victims for their bravery in coming forward after many years of silence; it is due to them that Cullen has pleaded guilty today and now awaits sentencing on March 24. Nothing can take away the horror of what happened to them, but I hope that today's verdict will help them in some small way to find peace.
"The abuse of children is abhorrent, by whomsoever it is perpetrated, as is any attitude of mind which somehow tolerates it. The Catholic Church takes the safeguarding of children and vulnerable adults extremely seriously, and it is our hope and expectation that no child or vulnerable adult should ever suffer at the hands of others. We will continue to work with the police and other statutory authorities whenever allegations of abuse arise, and will ensure that our churches and parishes are safe and welcoming for all members of the community."