Goncalo was part of the police investigation into Madeleine’s disappearance from a resort in Portugal’s Algarve region in May 2007.
In 2008, the retired police officer published a book about the case entitled: Maddie: The Truth About The Lie.
In the book, Amaral claims that Madeleine had died in the holiday apartment where the family were staying, and also claimed Kate and Gerry faked her abduction to cover up the tragedy.
Despite many of the country’s top detectives insisting there is no evidence to support Goncalo’s claims, the book became a bestseller in Portugal; and Amaral was sacked as head of the investigation after the book was published.
Kate and Gerry took Goncalo to court over his claims, which they said “totally destroyed” them and felt “ashamed” that they might appear to have been blamed for their daughter’s disappearance.
The 57 year old former policeman was ordered to pay £380,000 in libel damages, however in April this year, Portuguese judges overturned the payout after Amaral appealed the ruling.
Speaking to the Associated Press about the decision, Amaral’s lawyer said: “The appeals court decided that he had the right to do what he did. It said he can write what he wants.
“It absolved him, said he didn’t have to pay anything.”
To help the Goncalo with legal costs, some of his British supporters set up a GoFundMe page, which raised over £50,000. The page has since been closed down.
In an online post, Goncalo thanked his supporters after he won his appeal, saying: “None of this would have been possible without you."
But now, lawyers for Kate, 48, and Gerry, 47, have submitted an appeal to Portugal’s Supreme Court, after the ruling was overturned.
A friend of the parents told The Sun: “They are exasperated by this. The longer it goes on the more anguish it causes.”
Maddie’s parents will use money from the Find Maddie Fund to pay the legal bills if the appeal is not successful – the fund which was set up using public donations to help search for their missing daughter.
A family source told The Sun: “We hope the appeal will be successful. If they lose there will be a big legal bill to pay, which will come from the fund set up to find Madeleine.
“When Operation Grange ends Kate and Gerry will have to finance their own private investigation again. They will never give up searching for Madeleine and worry that the continuing legal action could wipe out money they had put aside for this.”
Madeleine McCann was three-years-old when she disappeared from her bed in a holiday apartment in Portugal in May 2007.
Maddie’s parents, Kate and Gerry, had left the little girl and her two-year-old twin siblings sleeping in their holiday home as they dined with friends at a restaurant 50 metres away.
They checked on the children throughout the evening, at roughly half-hour intervals, until Madeleine's mother discovered she was missing at 22:00.
Since then, they have campaigned tirelessly for information as to their daughter’s whereabouts.
It has been nine years since Madeleine McCann disappeared - and she would now be 13-years-old.
On 3rd May 2016, the anniversary of Madeleine’s disappearance, her parents shared a message on their Find Madeleine website.
It read: “As yet another anniversary comes around, we’d like to thank all our supporters for your continued help and commitment in the search for Madeleine, and the hope for her safe return.
“It has been a very long time but the investigation continues, information is still forthcoming and our hope and resolve continue. Until we have answers, until there is news, there will always be hope and we will continue to do everything we can to help find Madeleine.
“The charity Missing People is releasing the single I Hope on May 20 ahead of International Missing Children’s Day. Please support the charity to help all missing children and their families by downloading the song.”
Tragically, the couple are still no closer to finding out where Madeleine is - or what happened that fateful night in Praia Da Luz.
However, in a new interview, police officers have revealed that there is a chance that Maddie could be found alive - nine years after her disappearance.
Detective Chief Superintendent Mick Duthie, the head of Scotland Yard’s homicide squad told the Evening Standard: “There is ongoing work. There is always a possibility that we will find Madeleine and we hope that we will find her alive.
“That’s what we want and that’s what the family and the public want and that is why the Home Office continue to fund it.”
He added: “There is work that needs to be done still.”
It was recently revealed that Scotland Yard had been given more money to help with the Find Maddie investigation - but the funds came with a time frame.
They now look set to close the investigation in six months, whether or not they manage to track down the little girl.
Operation Grange will now continue until early October, until the extra £94,592 runs out.
Once the money is gone, Scotland Yard will have to end the five-year inquiry, which has cost £12 million already.
A Home Office spokesperson said: “Following a request from the Metropolitan Police Service, we have agreed to provide nearly £95,000 of further funding for Operation Grange.”
A Scotland Yard spokesperson said: “The inquiry has not reached a conclusion. There are still focused lines of investigation to be pursued.
“There are no immediate plans to reduce office numbers further at this time.”
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