Caldey Island was once known for being “crime free”, but in 2017, six women settled a civil claim against the abbey.
They had been sexually abused as children by the monk Thaddeus Kotik.
The former abbot Robert O’Brien knew about the abuse but did not report it.
An independent review, published in 2024, found that victims were treated in a heartless, hostile and cruel way.
It said frequent allegations of abuse were made, but not followed up on or reported to police, and the lack of challenge had enabled Kotik to abuse children over four decades “in plain sight”.
Other offenders have also stayed on the island, including a man who was wanted by police and lived under an alias for seven years before being jailed for 30 months for possessing child abuse images.
The abuse by Kotik was investigated by the police in 2014 and 2017, but officers concluded there was little they could do as he died in 1992.
However, a former head of crime for the force has called for a renewed investigation into the abuse by Kotik, which could also look at how three other offenders – Paul Ashton, John Cronin and John Shannon – came to stay on the island.
Steve Wilkins, who led the operation behind the conviction of serial killer John Cooper, said: “Was the magnet that drew them there that they could go and hide in plain sight?
“They could continue their offending with little chance of it being reported to the authorities.”
Dyfed-Powys Police said it had followed all appropriate lines of enquiry and there were no ongoing investigations.
Rossey apologised and acknowledged child abuse was previously ignored.
He said it was deeply concerning people felt unable to speak up or feared exclusion if they raised concerns.
He said things had changed on the island, that new safeguarding measures had been introduced including a committee with police, council staff and a survivor of abuse.
People who live and work on the island must now have criminal record checks, original ID and have interviews with the abbot and island manager.
He said the abbey was committed to openness, listening to those harmed and learning from past failures.
He said all recommendations from an independent review into abuse on the island had been implemented.