Police have identified a body found on a north Wales beach 33 years ago as that of a 63-year-old Irish man from Kilkenny.

The body was brought ashore by the tide and found by an RAF airman who was running on Rhosneigr beach, Anglesey, on the morning of 9 November 1985.

Attempts to identify the remains failed due to the limited nature of forensics at the time, and an inquest returned an open verdict. The death was not treated as suspicious and the body was buried in an unmarked grave.

Following an investigation by North Wales police and the Garda missing persons bureau in Ireland, the remains were exhumed – after a graveside blessing from a local priest – on 19 June and tested using the latest DNA technology.

Police now believe the body was that of Joseph Brendan Dowley, a father of four who had been living in London. He was last seen in October 1985 when he boarded a bus in Kilkenny to catch a ferry to Holyhead.

DS Don Kenyon of North Wales police, the officer leading the operation, said: “We have received a very positive result from the familial DNA analysis of the remains exhumed from Menai Bridge Cemetery on 19 June.

“The DNA report has been sent to coroner Dewi Pritchard Jones, who has already been provided with a full file of evidence in relation to the case of missing person, Joseph Brendan Dowley.

“Dowley’s family have been kept updated with this most recent development and Pritchard Jones will now consider the entirety of the case to establish if there is sufficient evidence to make a formal identification.”

The man’s son, Alan Dowley, told the Irish broadcaster RTÉ: “I want to thank the North Wales police, gardaí and Forensic Science Ireland for all their work on this case.

“I am glad we have had a positive result. It provides closure for our family, an inquest will be held in Wales and we can make arrangements.”

He had contacted North Wales police after another body washed up on the Welsh coast was identified as Pauline Finlay, who disappeared while walking her dogs on a beach in Kilmuckridge, County Wexford, in 1994. Leg and hip remains were found at Cable Bay in Holyhead, seven months after her disappearance, but were only formally identified in 2016.

Alan Dowley had obtained medical records for his father from St Mary’s hospital in London, which showed he had scars from hernia and kidney operations that matched him to the body that appeared on the beach.

Speaking last year, Alan Dowley said he had fond recollections of fishing with his father as a child. “He liked the good life. He left the family when I was a teenager. Back in the 80s he went to work in England,” he said.

“My sister put him on the bus in MacDonagh station in Kilkenny on 17 October 1985, and that was the last we ever heard from him then,” he said. Joseph Brendan Dowley’s decomposed body washed up in Anglesey three weeks later.

“Eventually, when there was no contact and everything turned out negative through checking with his bank … we presumed that something must have happened, and as a result of that I made a formal report of him missing,” he said.

The exhumation this year followed an investigation under North Wales police’s Operation Orchid, in which detectives used modern DNA technology to help identify human remains discovered in the region over the past five decades.

Kenyon said the operation was designed to help “bring some closure to families who have lived with uncertainty for such a long time”.

“Criminality is not suspected in any of the cases and the focus of the operation is simply to identify, reunite and allow the dignity of a funeral service for family and friends to pay their respects,” he said.