Madeleine McCann's mother may have been just moments away from catching her daughter's abductor, according to new details released by police.
Detectives say they now believe a man seen carrying a child a few hundred yards from the family's apartment at around 10pm was the three-year-old's kidnapper.
The sighting - which came at around the same time Kate McCann checked on her three children - had previously been considered of less significance than an earlier, now-discounted sighting.
When asked how convinced he is that the later sighting was of Madeleine, Detective Chief Inspector Andy Redwood told Sky News: "The timing and location speak for themselves."
For six years, detectives believed a man seen carrying a child close to the apartment at around 9.15pm was their key suspect.

Two e-fits of the new suspect have been made public
But a review of the evidence has concluded that it was an innocent British holidaymaker carrying his daughter home from a creche.
It means the inquiry has now switched its focus to the second, later sighting - and police have already received more than 100 new calls as a result.
The developments were revealed as part of a televised appeal and reconstruction on BBC Crimewatch.
Police said they were "very pleased" with a response that has seen nearly 500 people contacted them with fresh information since last night's show.

The Metropolitan Police's Operation Grange has been reviewing the evidence gathered by both the Portuguese police and private detectives, and has come to a conclusion which officers say completely changes the timeline of what happened on May 3, 2007.
Madeleine's parents had been dining at a restaurant in the Algarve tourist resort of Praia da Luz.
They had been taking it in turns with a group of friends to check on their children, who were asleep in nearby apartments.
During one of these checks at around 9.15pm one of the friends, Jane Tanner, saw a man walking along the street carrying a child in his arms.
She thought nothing of it, but within an hour Mrs McCann checked the bedroom where Madeleine and her younger twin brother and sister had been sleeping, and discovered that the little girl had gone.
Although the Portuguese police did not publicise the sighting and instead made the parents suspects in the case, once their investigation closed the McCanns arranged for a sketch to be drawn showing the man Miss Tanner had seen.

The McCanns have never given up hope of finding their daughter alive
Ever since it has been central to how people have viewed the case.
But Scotland Yard detectives reviewed the evidence and realised that around a dozen holidaymakers had been using a free creche at the Mark Warner resort, and would have collected their sleeping children during the evening.
One of those parents was contacted by police and said he may have been the man - and had been wrongly identified as a possible suspect.
He agreed to pose for a photograph so his build could be compared to the sketch.
That, together with evidence that his two-year-old daughter was wearing similar pyjamas as the sketch, has convinced the man leading the inquiry that this sighting is wrong.
DCI Redwood told Sky News: "As you can see from the images we've put forward, both from what the man was probably wearing and the actual physical location he was in, and the description of the child he was carrying, it is highly compelling.

Jane Tanner, a friend of Gerry and Kate McCann
"We believe in a convincing way that this is not Madeleine's abductor."
That information means that it seems likely that Madeleine was taken from the apartment slightly later than first thought, shifting the focus to the second witness statement.
An Irish family on holiday in Praia da Luz had told investigators that they saw a man carrying a child towards the beach at around 10pm.
Their sighting was closer to the town centre on Rua da Escola Primeria.
While the evidence is not new, two e-fits of the man which the witnesses helped create have now been made public.
The e-fits were made in 2008 by private detectives working for the McCanns, but were not made public because they seemed less relevant than the 9.15pm sighting by Jane Tanner.

A 2007 sketch of a suspect based on Miss Tanner's sighting - now ruled out
DCI Redwood said he realised that the man seen later could also be entirely innocent, but appealed for help from the public in identifying him.
"This child is described as being about three to four with blonde hair, possibly wearing pyjamas, and the man is white with dark hair," he said.
"If this is you, and you are nothing to do with Madeleine's disappearance, then we really need to speak to you. It's so important for us to eliminate innocent sightings.
"But equally if anybody is looking at those e-fits and recognises the person, for whatever reason, then please have the courage to call in and tell us."
The Metropolitan Police team refuses to be critical of the previous inquiry in an effort to foster good relations with Portuguese police.


E-fits of men the police want to speak to in connection with the case
Six local officers based in Faro have been appointed to liaise with British police. But DCI Redwood hopes that ultimately the Portuguese investigation will be reopened.
He told Sky News: "Reopening the inquiry is a matter wholly for the Portuguese and we completely respect and acknowledge the differences in our system.
"But of course our aspiration is to have the case reopened so we can work together with our Portuguese colleagues jointly so we can establish what happened to Madeleine McCann."
DCI Redwood is also hoping to get more information about men seen in the vicinity of the McCanns' apartment on several occasions in the week she disappeared.
When asked whether he believed the family were being watched, he said: "The physical evidence demonstrates to us that there are people, unexplained people, possibly doing just that.
"By the way the witnesses have described them ... lurking around in the very close proximity from where Madeleine was taken."


The e-fits are based on witness accounts of men seen in the area
British police have also revealed that there was an upsurge in the number of burglaries in the resort in the weeks leading up to May 2007.
Exactly a year earlier there was also an incident in which a child raised the alarm after seeing an intruder in their holiday apartment.
The police are looking at whether these incidents could be related.
And they have also released e-fits of men described as "charity collectors" who had been going door-to-door and may or may not be genuine.
Officers think there is a possibility they could have been checking apartments ahead of a possible break-in.
British officers are well aware that many residents of the Portuguese town have become fed-up with the constant media attention.
But he made this direct appeal to them: "What I would say specifically is that this change of emphasis in terms of the timeline between 9pm and 10pm means we can genuinely ask the public in Praia da Luz to go back over that time and look at those efforts.
"And if you recognise someone in the local community - please have the confidence to come forward to us."

The police probe has switched to a second sighting
The new appeal formed part of the BBC Crimewatch programme which featured a detailed reconstruction of the McCanns' visit to the resort.
Madeleine's parents, Gerry and Kate McCann, appeared live in the studio and said they were "feeling hopeful and optimistic".
"These cases can get solved and that's what the public need to think about tonight," said Mr McCann.
"We don't know what's happened to Madeleine, we don't know who's taken her. The best chance of finding her is by identifying (the person who took her)."
Mrs McCann said: "It doesn't matter how much heartache we put ourselves through as long as we get the result that we need."
She appealed to viewers to have "the courage and confidence to come forward", adding they could hold the key to "unlock" the case.
The last photographs of Madeleine which have been iconic because of their repeated use in appeals over the years, were brought to life by recreating the moments they were taken - Madeleine holding tennis balls and sitting at the side of a swimming pool.
There was also previously unseen family video of Madeleine.
:: Sky News will show a special investigation tonight at 8.30pm on Sky Channel 501, Virgin Media 602 and Freeview 82