A leading DNA scientist, who appears in the podcast Maddie, says he believes he can answer the forensic question that has baffled Madeleine McCann investigators for years.
The expert - whose lab helped identify the victims of the September 11 terror attack says DNA samples from the McCann's holiday home and rental car could change the whole case despite a judge concluding the tests were inconclusive.
Portuguese sniffer dogs discovered the scent of death and human blood inside the family's rental car, three weeks after Maddie vanished.
However, the UK's Forensic Science Service's analysed sample results in 2007 came back inconclusive and failed to decipher any potential evidence.
The DNA expert's world-renowned lab has since tested the same DNA, highlighting the UK's Forensic Science Service testing methods used in 2007 is now outdated.
The inconclusive data cast doubts over the work of the search dogs, however, the DNA expert believes more needs to be looked into the dog's investigative work.
He says if a lab can produce new data it may blow open the case.
"[The FSS testing] failed in this case 10 years ago," the DNA scientist said.
"If a lab can produce informative data, even if it is complex and mixed, but they can't interpret it then you can have tremendous injustice - of guilty people not being convicted, or innocent people staying in prison. What is needed is an objective and accurate interpretation that can scientifically resolve the DNA."
The US forensic lab now has a global reputation for solving previously indecipherable DNA samples, playing a pivotal role in many high-profile trials.
The two dogs, named Eddie and Keela, were hand-picked by the UK police force's national search expert.
Eddie and Keela made 13 alerts in several key locations inside the apartment and in the rental car.
Both dogs alerted authorities on their silver rental car 25 days after Maddie vanished, and alerted their handler to several items on Kate McCann's clothing and Maddie's favourite soft toy.
In a report filed by UK police expert Harrison after the search, he wrote: "No inference can be drawn as to whether a human cadaver has previously been in any location without other supporting physical evidence."
The McCann's have denied any involvement in the disappearance of their daughter Maddie.