The Barcelona-based detectives, who began working for the McCanns two months ago, are now compiling a hit list of Portuguese pedophiles known to target girls Madeleine’s age.
They will then send their international network of agents to trace the exact movements of their prime suspects before and after May 3 – the day the youngster disappeared.
The managing director’s Francisco Marco, 35, told the News of the World: “I’m certain Madeleine was kidnapped. “And I’m also sure her parents had nothing to do with her disappearance.
“My own view is the most likely place to find her is Morocco. We’re working very hard on all information indicating that. But I stress that we are following up everything.”
Metodo 3 launched a special hotline and email appeal for information last week after Kate and Gerry - both still branded suspects by Portuguese police - gave an emotional interview on Spanish TV.
In three days the agency received 400 calls.
This fresh hope for the Kate and Gerry, both 39, comes as plans to use new laws to access the Portuguese police dossier on them were dashed. They could have to wait 11 months.
A source said: “Kate and Gerry now have great faith in Metodo and are very impressed with its record. “From information already gathered the strongest indication is that this abduction was very carefully planned.”
Metodo investigators are already working extensively on the ground in Morocco to identify the monsters and where they operate.
The agency’s theory ties in with witness statements detailing timings of events on May 3 and the daily routine of the McCanns.
A recent computer reconstruction of that night - when the McCanns and friends dined in the nearby tapas bar - indicated a kidnapper would have had just eight minutes to strike.
That meant inside knowledge was crucial.
There have also been a string of sightings in Morocco of young girls resembling Madeleine. Six days after she vanished, Norweigan-born Mari Pollard, 45, said she was “100 per cent certain” she saw Madeleine at a garage in Marrakesh.
In September it emerged a second sighting had already been reported by a holidaymaker from Yorkshire in a hotel opposite the garage.
Then Jeannie Thompson, 56, from Devon said she saw a blond girl looking “disheveled” as a man took photographs of her at the Cafe des Epices in Marrakesh on May 11.
Three more women have since come forward with sightings.
Morocco has a reputation as a haven for pedophiles and Kate and Gerry paid a two-day visit earlier in the hunt to meet the Interior Minister and conduct a series of talks with child protection officers.
