While the parents of Madeleine McCann learned Wednesday that a blond-haired girl in a tourist picture from Morocco was not their daughter, the British press reported earlier this week that the family had hired a private security firm to help look for the missing toddler.
Sources close to the family told British media that Kate and Gerry McCann had retained the services of Control Risks Group — an international company that employs former members of the British intelligence services and the army — because they mistrust the way the Portuguese police have handled the search for Madeleine.
Madeleine disappeared from a holiday flat in the Portuguese resort Praia de Luz on May 3, six days before her fourth birthday. Despite numerous reported sightings in Europe and North Africa, the child's trail appears to have gone cold.
A spokeswoman for Control Risks Group, which has 18 offices worldwide, but is based in London, would not comment on any dealings with the McCanns, telling ABC News only, "we don't confirm or deny who we're working for."
The McCanns have not confirmed their involvement with Control Risks Group or commented on how the company might be paid.
But a source close to the family's legal team told British newspaper The Times, "Control Risks are one of the groups who've offered their services to the McCanns. You can assume they are doing some things that the Portuguese police can't do."
What those things are, no one can say for sure. The operations of firms like Control Risks Groups are shrouded in secrecy. The company, which has more than 600 employees and describes itself as an "independent, specialist risk consultancy," offers services such as "video forensics" and "crime scene reconstruction," and is one of the largest British private security firms active in Iraq.
It promises clients absolute anonymity and will not comment on its methods. Its personnel is said to range from former intelligence officers to members of the British Special Forces.
But while Control Risks would not comment on its techniques, in interviews with ABC News several industry insiders not involved in the case sketched out how such a private firm might go about finding Madeleine.
A private investigator in charge of the case would likely "start with the parents, Mr. and Mrs. McCann," said Cliff Knuckey, a former detective inspector with Scotland Yard and managing director of the private investigations firm Risc Management.
They would work outward from there, Knuckey said, "to the circle of relatives, and the circle of friends that were there in Praia de Luz. Just to help piece together a profile."
Roy Ramm, a former commander of specialist operations at New Scotland Yard and chairman of the British private security firm Commercial Security International, also said private detectives would start with those closest to the case.
"Basically what they'll do is re-interview all the witnesses, going back over it in a methodical way," Ramm told ABC News. "They'll try to get to a point where they either do a physical or virtual reconstruction of what happened and literally start again. But to do it without the kind of preconceptions that seem to have beset the Portuguese investigation."
Portuguese detectives have said they have checked out more than 400 tips across Europe and North Africa about Madeleine's disappearance. But the McCanns, who were named official suspects in the investigation earlier this month, have expressed concern that not all leads have been properly investigated.
They worried especially, according to British media reports, about two sightings on the same day by a Norwegian and a British tourist near the Moroccan city of Marrakech six days after Madeleine disappeared. Both tourists later complained the Portuguese police did not give their reports the attention they deserved.
Knuckey said that in cases of such international sightings, especially, private investigators could have the upper hand over regular police forces.
"If the Portuguese police make a request of the Moroccan police," Knuckey said, "it becomes a very long bureaucratic affair. Control Risks can cut all that out, because they're not hamstrung by diplomatic bureaucracy."
He added that private security teams are not hindered by the kinds of regulations that he said can sometimes constrict regular police forces.
"Again, the police are hamstrung with bureaucracy," Knuckey told ABC News. "When they're talking about informants, there are all sorts of guidelines and rules to abide by. It's all about dotting the I's and crossing the T's."
"The corporate sector is not required to adhere to that at all," Knuckey said.
Gerry McCann reportedly approached several private investigation companies in May, just weeks after his daughter went missing.
The McCanns have explicitly denied sending private investigators into Portugal after it became clear that it is illegal to hire private help in Portuguese criminal cases. But they have not denied reports that private investigators are looking for Madeleine elsewhere, such as Morocco and Spain, where a number of sightings have also been reported.
It is not clear how much a company like Control Risks Group would charge for its services, though one industry insider speculated to ABC News that it could cost up to $50,000 a month to keep the firm on retainer.
Financial supporters of the McCanns include billionaires Richard Branson and Sir Philip Green.
On the question of whether private eyes would have a chance at finding Madeleine nearly five months after she went missing, industry insiders couldn't agree.
"It's a long shot," said Peter Heims, the public relations officer and past president of the Association of British Investigators. "They're grasping at straws. But if you've only got straws to grasp at, well, then you gotta go that way."
Knuckey of Risc Management said private detectives would not be able to find Madeleine without a new lead in the case.
"They're never going to solve the disappearance," Knuckey said, "because to have a chance at doing that they would have to have access to all of the material that's been gathered by the Portuguese investigators. And that's not going to happen."
"But where they do stand a chance," he said, "is if there's a genuine sighting of Madeleine McCann. Then they will get people on the ground quicker than law enforcement will."
Ramm was more optimistic.
"I think it could make a difference," Ramm said of private investigators' possible involvement in the case. "Because I have real doubts that witnesses have been interviewed as thoroughly and professionally as they should have been."
"If very good, experienced homicide investigators or just good detectives get to those witnesses," Ramm said, "and go through it from the top, there is a chance that something has been missed."