Scotland Yard has wasted almost $20 million investigating "ridiculous" theories that Madeleine McCann was abducted, according to a US criminal profiler.
Pat Brown, a profiler of cold cases in America and a regular guest on major US TV networks, said she was baffled by British police who failed to carry out a "proper investigation".
Operation Grange was launched by London Metropolitan Police in 2011, after Madeleine McCann vanished without trace from her family's Portuguese holiday apartment in May 2007.
The case, which continues to fascinate the world, remains unsolved.
US criminal profiler Pat Brown (right) appears on TV network CBS to discuss the Maddie McCann case in 2010. Source: CBS
"What Scotland Yard was doing was not a proper investigation," Brown told Nine.com.au.
"Scotland Yard went in saying the McCanns are not suspects, and that [the disappearance of Maddie] is an abduction. There is absolutely no way you should have entered an investigation saying that."
Scotland Yard is one of the world's most respected crime fighting agencies, making its approach doubly confusing, Brown said.
"Their focus has always been there was an abduction and we're going after a kidnapper."
Everyone, including parents Gerry and Kate, should have been suspects when Operation Grange was opened following a 2011 request by now British Prime Minister Theresa May, Brown said.
"They spent a tremendous amount of time following the most ridiculous leads ever. It was like watching a massive charade.
"To this day it's made no sense. They've spent an incredible sum of money going absolutely nowhere, coming up with absolutely nothing – not even a piece of evidence to add to the evidence we already know about."
This week Operation Grange was granted another $137,200 to cover operational costs through to September 17, a period that will include the 10th anniversary of Maddie's disappearance on May 3, 2007.
An unnamed source inside Operation Grange, which to date has been funded to the tune of $17.9m by the British government, claimed it was "a last throw of the dice".
Brown told Nine.com.au she believed Scotland Yard was handed a political football, where the results of the investigation did not matter.
The American profiler has spent countless hours poring over the entirety of official case files that were released by Portugal's Policia Judiciaria. She has also visited the town of Praia Da Luz.
Policia Judiciaria investigated the disappearance of Maddie, who would now be aged 13, between 4 May 2007 and 21 July 2008.
A picture of Madeleine McCann taken when she was three years-old (L) and a computer generated handout image released by the Metropolitan Police Service showing Madeleine might have looked in 2012, aged 9.
In September 2007 Gerry and Kate were sensationally named as 'arguidos' (a person being questioned under caution) by Portuguese police.
Goncalo Amaral, the detective who headed up the original investigation, claimed Gerry and Kate McCann covered up their daughter’s death in his book and a documentary.
The McCanns, who have always staunchly declared their innocence, last month lost their court battle to silence the former detective.
Brown met with Amaral while she was in Praia Da Luz, exploring key locations and surrounding areas relating to the case.
"There is evidence to lead one to believe the top theory should be Madeleine is dead," declared Brown.
Gerry (L) and Kate McCann, whose daughter Madeleine went missing from her family's holiday flat in the Algarve shortly before her fourth birthday in 2007, attend the recording of the "Beckmann" TV show where they presented their book 'Madeleine' on September 15, 2011 in Hamburg, Germany. Source: AFP
She said, having looked at all the evidence, there was "zero sign of abduction".
Operation Grange has investigated theories involving child sex traffickers and Maddie's abduction by burglars or pedophiles.
The child trafficking theory was initially raised by private investigators hired by the McCanns in 2007.
COMING NEXT: How Pat Brown's book on the Maddie McCann case was shut down on Amazon. Follow me to read the next instalment of Pat Brown's explosive interview with Nine.
Read more at http://www.9news.com.au/world/2017/03/14/14/50/maddie-madeleine-mccann-abduction-theories-blasted-as-ridiculous-by-us-crime-expert-pat-brown#QaRObG4086i1wPP0.99