Evidence recently presented as a "breakthrough" in the hunt for Madeleine McCann was reportedly produced for her parents by a group of former spies in 2008.
Kate and Gerry McCann hand-picked a team of former MI5 agents after becoming fed up with the pace and direction of the original Portuguese investigation.
The intelligence report was kept secret for five years as it was deemed "hyper-critical" of the McCanns and their friends, reports the Sunday Times.
The contents were only made public after Scotland Yard investigators requested a copy when conducting a fresh review of the case
E-fits of a man seen at the time of Madeleine's disappearance shown on a special edition of Crimewatch last week and presented as new evidence are in fact from the 2008 report.
Detectives also said the accepted version of events surrounding the disappearance the little girl in 2007 had "significantly changed".
One of the authors of the 2008 report said he was "utterly stunned" the evidence had been presented in such a way.
Henri Exton, MI5’s former undercover operations chief, who led the group, confirmed they had been silenced by the McCanns.
He said: "A letter came from their lawyers binding us to the confidentiality of the report."
The Crimewatch appeal prompted thousands of calls from the public.
The news comes in the same week as Portugal's attorney general approved a police request to re-open the investigation into the disappearance of Madeleine.
The case was shelved in 2008 leaving detectives from the UK's Metropolitan Police Service to carry on the search.
Carrie-Marie Bratley of the Portugal news told Sky News: "There are people who are extremely supportive of the McCanns, there are people who are extremely sympathetic ... and they are very much interested in this case.
She added that officers in any new investigation would have had no involvement in the initial police operation and were chosen for "their emotional and physical distance from this case in the hope that maybe they could go over it with a fine-tooth comb and come up with something, which it seems they may have done."