Madeleine McCann’s parents have launched a fresh legal battle to overturn a Portuguese court ruling that failed to clear them of involvement in their daughter’s disappearance.

Kate and Gerry McCann’s lawyer confirmed they would use money from the “Find Madeleine” fund in a bid to overturn the ruling, and challenge claims by former police chief Goncalo Amaral that they had faked their daughter's abduction.

Portugal’s Supreme Court rejected their libel appeal last month relating to Mr Amaral’s 2008 book, “The Truth of the Lie”, that alleged their three-year-old daughter had died in their holiday flat and they had faked her kidnapping to cover up the tragedy.

The couple were successful in their 2015 libel action against the former police chief on the case, however a lower court overturned the decision in April 2016, opening them up to huge legal costs and the possibility of being sued by Mr Amaral.

The McCanns, both 48, reportedly decided to launch the new challenge based on comments made by the judges in the 76-page ruling, which stated the decision “was determined by the fact that public prosecutors hadn't managed to obtain sufficient evidence of the crimes by the appellants”.

The McCanns were considered official suspects at one stage, however their “arguido” status was lifted on the same day it was issued in July 2008.

Judges said the archiving of the criminal case did not equate to the McCanns being cleared of criminal responsibility.

Madeleine McCann: Unfinished business Show all 2 1 /2 Madeleine McCann: Unfinished business Madeleine McCann: Unfinished business pg-16-madeleine-1-pa-blythe.jpg Madeleine McCann pictured at the age of three, left, and as she might have looked aged nine PA/Teri Blythe Madeleine McCann: Unfinished business pg-16-madeleine-2-pa.jpg Kate and Gerry McCann believe that Madeleine is alive PA

"In truth, that ruling was not made in virtue of Portugal's Public Prosecution Service having acquired the conviction that the appellants hadn't committed a crime," they wrote.

“Even the archive ruling raises serious concerns relating to the truth of the allegation that Madeleine was kidnapped."

They also found Mr Amaral had not acted "illicitly" ruling the content of his book had no "defamatory intention" behind it.

"Our opinion is that rather than an injurious animus, the intention was informative and defensive,” they wrote.

The McCanns said in a statement after the ruling: ​"What we have been told by our lawyers is obviously extremely disappointing.