Competing British police forces searching for Madeleine McCann actually hampered the investigation, according to a secret Home Office report.
The author of the unpublished report – leaked to Sky News - says that although various UK authorities were trying to help in the weeks immediately following the three-year-old's disappearance in Praia da Luz in 2007, the competition between them has had a long-term, negative effect on the case.
The author, Jim Gamble, former head of the Child Exploitation and Online Protection Centre (CEOP), found that so many UK agencies got involved it damaged relations with Portuguese police.
The report, commissioned by former Home Secretary Alan Johnson in 2009, was delivered in 2010 and led to the Metropolitan Police reopening the investigation into Madeleine's disappearance, but was never released.
For the first time details have been leaked to Sky News, revealing that Mr Gamble criticised the Association of Chief Police Officers' decision to put Leicestershire Police in charge of the operation because the McCanns lived in the county, despite the fact the force was ill-equipped to deal with such a big investigation.
Mr Gamble said that within weeks of Madeleine going missing in May 2007 the Portuguese were given advice by CEOP, the Metropolitan Police, the Serious Organised Crime Agency and the National Police Improvement Agency.
The Crimestoppers charity published its own appeal hotline and different Government ministers – No. 10, the Home Office and the Foreign Office – were demanding briefings from the various agencies.
Mr Gamble said: "All of us, including myself at CEOP at the time, your first gut reaction is you want to help, a child has gone missing ... so everyone came with best intentions, that created a sense of chaos and a sense of competition, people putting their hand up and wanting to help and in many instances in my opinion wanting to be seen to help.
"If we look at it honestly there were some in leadership roles who wanted to represent their organisation, to be seen to take a lead role and be seen to provide critical input in this and that made it difficult for a small, regional force like Leicestershire.
"It was unhelpful ... I've no doubt relationships from the outset with the Portuguese were impacted by it and I think that had a long term negative effect on the investigation and I think to this very day the Met investigation team that's engaged now are still having to manage and massage that relationship and perhaps to be fair to the Portuguese, mend some fences that were trodden on in the early days."
Discussing the investigation Mr Gamble said that the initial Portuguese police response to Madeleine's disappearance was 'haphazard'.
He said: "There was chaos, and as it went on it was haphazard, which was alien to the more structured police you would expect here in the UK. There was not a sense of order.
"In the first instance the parents should be your Number One suspects. In most cases in the first few golden hours as you collect evidence you can then rule them in or out.
"And that was one of the huge flaws in this, that people didn't focus on clearing the ground beneath their feet in those chaotic first few hours that led into the haphazard first few weeks.
"When I carried out the scoping review there was no evidence that some of the critical information and the analysis of which could have led to intelligence and to leads had been followed up."
One of Mr Gamble's recommendations in his report was the establishment of a national centre for missing children which could combine the resources of the best experts and technology.
However, this has not been set up and therefore the British authorities are no better equipped to deal with a similar situation than they were in 2007, Mr Gamble warned.
Despite the failings Mr Gamble remains confident that Madeleine's case will be solved.
He said: "Someone knows ... I genuinely believe in my lifetime we will find out what happened. Relationships, loyalties change, and at some stage some person will come forward."
The Home Office – which declined to release the report under Freedom of Information laws – declined to comment.