Missing Madeleine McCann's parents have confirmed they are fighting a Portuguese court decision to side with former police chief Goncalo Amaral over his hurtful claims about her disappearance.
The country's Supreme Court last month rejected their last-ditch appeal over his 2008 book The Truth of the Lie in which he alleged Maddie died in their holiday flat and they faked her abduction to cover up the tragedy, the Daily Mail reports.
Judges backed a lower court's April 2016 decision to reverse their 2015 libel win against the ex-detective, leaving the couple facing a huge legal bill and the nightmare prospect of being sued by Amaral.
And they also challenged Gerry and Kate's insistence they had nothing to with their daughter's disappearance in a devastating put-down which is said to have sparked their fresh legal challenge.
The McCanns have now confirmed they are seeking to get the Supreme Court decision invalidated after launching a formal complaint against the judges' findings.
It was known they had 10 days to file an objection with court officials.
It is thought the McCanns' attempt to nullify the decision is based on comments made by the judges in their 76-page ruling that the 2008 shelving of the Portuguese probe into their daughter's disappearance "was determined by the fact that public prosecutors hadn't managed to obtain sufficient evidence of the crimes by the appellants."
The McCanns had their status as 'arguidos' or official suspects lifted on the same day - July 21 2008 - just three days before Amaral published his controversial book.
Correio da Manha reported: "The McCanns have requested the annulment of the Supreme Court decision, terming it frivolous for saying it "had not been possible for public prosecutors to obtain sufficient evidence of crimes by the appellants."
The newspaper said the McCanns had described the ruling as 'leviano' in the complaint lodged through their Portuguese lawyer - which in English translates as 'frivolous' but can also mean 'sloppy' or 'rash'.
No-one from the Supreme Court was available for comment this morning.
The McCanns' lawyer Isabel Duarte, asked if she had lodged a formal complaint against the Supreme Court ruling, confirmed: "We delivered it."
It was unclear today if another set of Supreme Court judges dealt with complaints about rulings - or they were handed to another judicial body to deal with.
Amaral was ordered to pay the McCanns €500,000 euros ($430,000) by a Lisbon court in April 2015 after they won round one of their lengthy judicial battle over his book and a subsequent TV documentary.
"However even the archive ruling raises serious concerns relating to the truth of the allegation that Madeleine was kidnapped."
The Supreme Court judges said the McCanns claimed Amaral's book and the TV documentary based on the book formed no part of case files made public in 2008 and would have damaged the honour and good name of any "innocent person who had been cleared through the shelving of the criminal investigation."
But they stated: "We consider the invocation of the violation of the principle of innocence should not be taken into account here, since this issue is not relevant to the resolution of the question that needs to be decided here."