Two men have been jailed for life after being found guilty of murdering a woman who was planning to report them for abusing a young boy.
Convicted paedophiles Charles O'Neill, 47, and William Lauchlan, 33, had denied killing Allison McGarrigle, 39, in 1997 and dumping her body at sea.
But a jury at the High Court in Glasgow found them guilty by majority verdict.
O'Neill was told that he must serve at least 30 years in prison while Lauchlan must serve at least 26 years.
They were also jailed for 10 years each for the sexual abuse of boys, aged six and 14, of which they were found guilty last month at the same court.
In a statement following the guilty verdicts, the McGarrigle family said: "Lauchlan and O'Neill have taken away the best mum in the world."
Mrs McGarrigle, whose body has never been found, was reported missing in 1998 and declared dead in 2005.
During the trial the court heard how Mrs McGarrigle had met O'Neill and Lauchlan in 1994 after moving to Rothesay, Isle of Bute, following her split from husband Robert.
She was introduced by the boy they went on to groom and abuse, and who years later was found hiding in their cupboard.
Mrs McGarrigle lived in fear of them and had threatened to tell police about their abuse of the child.
On 20 June 1997, she argued with the pair before being pushed by Lauchlan.
The mother then yelled: "I know what you are up to I will make sure I see what is coming to you."
Mrs McGarrigle went to her bed, but when the boy awoke the next morning, he found she had gone.
The pair had killed Mrs McGarrigle whose corpse was put in a wheelie bin and then dumped at sea.
She was eventually reported missing by her estranged husband in 1998.
The court heard how O'Neill and Lauchlan had made references to what they had done.
One boy, now 27, told the court that he heard O'Neill making comments that "chilled him to the bone".
The witness told the trial that O'Neill said she was "feeding the fishes down there" as he nodded towards the Firth of Clyde.
Drink driver John Molseed was in Barlinnie Prison in 1998 with O'Neill who told him she had been "done away with".
Lauchlan also told a plasterer, Keith Denenny, whom the pair met in Spain in 2004, that Mrs McGarrigle had been "got rid of" and repeated that she was "fed to the fishes".
The same year that Mrs McGarrigle was formally declared dead, O'Neill and Lauchlan were charged with her murder.
They were released however after prosecutors decided not to go to trial at that stage.
The pair were eventually arrested - after several more instances of child abuse - during a police operation in 2008.
In May this year, before the start of the trial, they were convicted of grooming a six-year-old boy having earlier sexually assaulted a 15-year-old boy while they were living in Spain.
O'Neill was also found guilty of drugging and sexually assaulting a 14-year-old boy in Irvine, Ayrshire.
A court order prevented any reporting on those proceedings until the end of this latest case.
Jailing the pair for life, judge Lord Pentland said: "It is clear that you are both dangerous and determined predatory paedophiles and that you now represent a high risk to the safety of the public."
He noted that the pair had previously "served lengthy sentences of imprisonment imposed in this court for offences of child abuse" but this had not deterred them from "predatory criminality".
"In the whole circumstances, I must sentence you on the footing that you are highly ruthless and unrepentant individuals with no respect for the law or the values of a civilised society," the judge said.
He also told them that they may never be freed.
The McGarrigle family statement said: "Allison McGarrigle was a bubbly, happy woman with a heart of gold. She loved children and she was taken from us trying to protect a young boy from abuse."
The family said they "miss her terribly and wish that we could lay her to rest".