Madeleine McCann's parents speak out after losing 13-year legal battle with former detective inspector

Speaking of the outcome, the McCanns have said they were 'naturally disappointed' by the news of the overturning.

The parents launched the libel case against Amaral in 2013, claiming he had infringed on their family's privacy and ruined their reputation.

In 2015, a court in Lisbon ordered the former police detective to compensate the McCann's €500,000 (£440,000). However, the decision was later overturned by an appeal court in 2016.

Portugal's Supreme Court also threw out the case in 2017.

In response to the latest ruling, the McCanns lawyers released a statement on their behalf, which reads: "We are naturally disappointed with decision of the European Court of Human Rights announced today. However, much has changed since we started legal proceedings 13 years ago against Mr Amaral, his publisher and broadcaster.

"We took action for one and only one reason: Mr Amaral’s unfounded claims were having a detrimental impact on the search for Madeleine."

The McCanns argued that Amaral's claims that they had been involved in their daughter's disappearance could have resulted in people not being 'alert for possible clues' and not 'report[ing] relevant information to the relevant law enforcement agencies'.

"The focus is now rightly on the search for Madeleine and her abductor(s). We are grateful for the ongoing work by the British, German and Portuguese police.

"We hope that, with the help of the public, hard work and diligence we can eventually find those responsible for Madeleine’s disappearance and bring them to justice," the statement concluded.

Amaral had been the lead detective investigating three-year-old Madeleine's disappearance in 2007.

In 2008, a Portuguese attorney general closed Madeleine's case. Just three days after, Amaral released a book called, The Truth of the Lie, which alleged the three-year-old was dead and that her parents had hidden her body.

He also claimed the parents were involved during an appearance on a television documentary about Madeleine's disappearance.

While Gerry and Kate McCann were both officially identified as suspects during the investigation, it was only for a short period of time as they were cleared of suspicion in 2008.

In the most recent decision by the ECHR, it was ruled that Amaral was not to blame for the 'social relations' between the parents and members of the public and that he did not negatively impact the investigation into Madeleine's disappearance.

The ECHR stated: "The Court considered that, even assuming that the applicants’ reputation had been damaged, this was not on account of the argument put forward by the book’s author but rather as a result of the suspicions expressed against them, which had led to their being placed under investigation in the course of the criminal investigation (the prosecutor’s office decided to take no further action in July 2008) and had led to intense media attention and much controversy."

It stated that any damaged 'social relations' had subsequently been caused prior to Amaral's book's publishing, that the former detective had a right to freedom of expression and 'the national authorities had not failed in their positive obligation to protect the applicants’ right to respect for their private life'.

The court concluded: "While the Court understood that the book’s publication had undeniably caused anger, anguish and distress to the applicants, it did not appear that the book, or the broadcasting of the documentary, had had a serious impact on the applicants’ social relations or on their legitimate and ongoing attempts to find their daughter."

Despite their 'disappoint[ment],' according to PA, the McCanns are not planning to appeal the decision.