The night the McCanns were convinced they'd found Madeleine

Madeleine McCann has been missing since she vanished during a family holiday to Pria de Luz in Portugal in 2007. Photo / File

Investigators hunting for Madeleine McCann were so convinced they had found her that a plane had its engine running in preparation to collect the missing girl.

It is one of two heartbreakingly near-misses in the first 12 months after her 2007 disappearance that her parents had to endure, their media spokesman has revealed.

Clarence Mitchell, who has been heavily involved throughout the last decade, told how a blonde, English-speaking girl was located in Morocco, with other details leading detectives to a near-certain assumption it was Maddie.

Writing in the Telegraph, he said: "All the information coming back to us suggested heavily that it could be Madeleine, so much so that an aircraft was put on stand-by, with its engines running, waiting to fly to pick her up.

"Kate and Gerry sat tight. They had learned by that stage to be sceptical, not to give in to natural hope only for it to be dashed. They preferred to wait until the Moroccan authorities had checked it out. And when they did, it became clear she was not Madeleine."

The other incident came a few months previously, when Mitchell continuously received phone calls at 3am revealing that Maddie was at a farm, which matched a very distinct description, but again turned out to be a false lead.

Mitchell had been working with the McCanns full-time after initially serving as an adviser to them while working at the Foreign Office.

The former BBC journalist previously covered Princess Diana's death as a royal correspondent and stood as the Conservative parliamentary candidate for Brighton.

He set up his own communications consultancy last year.

Madeleine vanished from the family's holiday apartment in Praia da Luz in Portugal on May 3, 2007, when she was three years old - with her mother Kate saying the 10th anniversary is a "horrible marker of time, stolen time".

But former Scotland Yard detective chief inspector Mick Neville has revealed that Facebook's cutting-edge facial recognition software could help find Maddie, who would now be 14 years old.

When Facebook users upload an image the social media platform maps facial features and "recognises" other users - making tagging easier.

Neville, a forensics expert, believes the state of the art technology could be used to trace Maddie because of a distinctive blemish in her right eye.

Earlier this week British detectives working on the Madeleine McCann case said they are still pursuing 'critical' leads as the 10th anniversary of her disappearance approaches.

Metropolitan Police Assistant Commissioner Mark Rowley said there are "significant investigative avenues" that are of "great interest" to both the UK and Portuguese teams.

Officers have sifted through some 40,000 documents and looked at more than 600 individuals since 2011 with Rowley confirming that four people considered as possible suspects in 2013 have been ruled out.

Kate and her husband Gerry McCann, of Rothley, Leicestershire, have always vowed to never give up hope of finding their daughter.

Asked if police were any closer to solving the case than they were six years ago when the UK investigation was launched, Rowley said: "I know we have a significant line of inquiry which is worth pursuing, and because it's worth pursuing it could provide an answer, but until we've gone through it I won't know whether we are going to get there or not.

"Ourselves and the Portuguese are doing a critical piece of work and we don't want to spoil it by putting titbits of information out publicly."

Rowley said they are no longer the subject of further investigation and have been ruled out of the inquiry. Meanwhile, police working on the case continue to receive information on a daily basis.

He described the possibility of a "burglary gone wrong" as a "sensible hypothesis" which has not been "entirely ruled out".

The senior officer was asked about the theory of a sex predator being responsible for Madeleine's disappearance.

Rowley said: "That's been one key line of inquiry. The reality is in the modern world in any urban area if you cast your net widely you will find a whole pattern of offences.

"You will find sex offenders who live nearby. And those coincidences need to be sifted out, what's a coincidence and what may be linked to the investigation that you are currently doing.

"Offences which may be linked have to be looked at and either ruled in or ruled out."

Rowley said there was still a "lot unknown" in the case, adding: "All the different hypotheses have to remain open."