A man being questioned over the suspected double murder of a couple is believed to have been involved in the elaborate clean-up after the deaths.
Willie Maughan (34) and his Latvian girlfriend, Ana Varslavane (21), are believed to have been abducted and murdered by gangsters after they went missing on April 14, 2015, in Gormanston, Co Meath.
The gang, led by Cornelius Price (38), who remains based in the UK, have always been the only suspects in the shocking murder case.
The suspect has lived at Price's fortified compound in Gormanston for many years. He is originally from the Rochdale area of England and is the first person to be arrested in the five-year investigation into the couple's murder. Their bodies have never been found.
His arrest was welcomed last night by Willie Maughan's father, Joe, who said: "I pray to God that man will tell gardaí everything he knows and that he tells the truth to clear his conscience.
"Tomorrow is the 12th anniversary of the death of William's brother Michael and news of a criminal charge being got in the case on the anniversary would be a day of great joy for our family.
"We were very happy to get the news from gardaí yesterday morning that there had been an arrest because it shows that the case is still very much active and there is still hope that justice can be done for my son and Ana."
Yesterday's dawn arrest in Co Meath is the biggest development yet in the long-standing double murder probe.
"This lad is no criminal mastermind at all - he is essentially a gopher for the smarter and more serious criminals in Price's organisation," a source said.
In April 2017 gardaí failed to find any evidence of the couple when they carried out a dig near Monasterboice, Co Louth.
Days before this dig, they raided Price's compound as part of the double-murder probe.
It is understood that the 57-year-old who was arrested yesterday was present on that occasion but not arrested.
The man who was being held at Ashbourne garda station last night is also being questioned about the discovery of firearms near the compound on January 15, which happened as part of the wider Keane Mulready-Woods investigation.
Price's arch-enemies - who included slain criminal Robbie Lawlor - had planned to dump body parts of the murdered teenager at the compound.
The man is also being questioned about what gardaí described as "the discovery of a large quantity of ammunition".
This was found in a Gormanston field just days before Price had completed a three-year jail sentence for the reckless endangerment of a garda at Balbriggan garda station in 2014.
Price's gang, which is involved in the Drogheda feud because of its close links to the Owen Maguire faction, is also suspected in the murder of Benny Whitehouse.
Mr Whitehouse was shot dead at Clonard Street, Balbriggan, on September 25, 2014, in front of his partner as part of a separate feud.
The same gang is being investigated for a pipe-bomb attack at the home of Willie Maughan's sister in Rathfarnham in October 2015.
And it is suspected in an incident last August when the grave of Willie Maughan's brother was dug up at Bohernabreena Cemetery in Tallaght, Dublin.