Around 30 British detectives were working on the UK side of the investigation into the disappearance of Madeleine (pictured)
Netflix is making an eight-part documentary about the 2007 disappearance of Madeleine McCann.
The streaming service has not announced the release date but says the show will feature new interviews with key investigators.
It follows the success of last year's one-part documentary on wrongly jailed American student Amanda Knox and the hit series Making A Murderer.
It is not known if Madeleine's parents Kate and Gerry McCann will feature. MailOnline has contacted their spokesman for comment.
The documentary will likely air before they learn the result of their appeal to the European Court of Human Rights regarding the Portuguese ex-police chief who claimed their daughter is dead and they are responsible.
Goncarlo Amaral, 57, claimed in his book The Truth Of The Lie that the three year old died at Kate and Gerry's Praia da Luz holiday house and the couple covered it up.
The McCanns won a libel case against Amaral in 2015 and he was ordered to pay them 250,000 euros (£209,000) each in damages.
But this was overturned on appeal and that decision upheld in another court this April, meaning Amaral is now able to sue the McCanns for damages potentially totalling tens of thousands of pounds.
To prevent this, Kate and Gerry, both 49, have lodged an appeal with the European Court of Human Rights. They now wait for the date of their Strasbourg showdown with Amaral to be confirmed.
Kate and Gerry outside court in 2014 when they successfully sued Amaral for damages over the claims he made in his book
Former detective Goncalo Amaral (pictured) wrote a widely discredited book saying Madeleine died in the house
A source close to the couple told The Sun: 'They discussed the situation with their legal team and they decided that ultimately it was worth fighting the decision of the Portuguese court.
'They are upset that the court made this ruling but are also desperately upset at Amaral's claims which are ludicrous and hurtful.'
Family spokesman Clarence Mitchell told MailOnline: 'I can confirm that Kate and Gerry McCann’s Portuguese lawyers lodged an appeal