British police are re-examining a theory that Madeleine McCann left her family’s holiday apartment to look for her parents when she disappeared more than a decade ago.

The latest revelation comes amid reports that Scotland Yard has told her parents Kate and Gerry McCann they are pursuing two vital new leads.

According to an exclusive by The Sun, one of these revolves around three-year-old Madeleine waking up and wandering out of the villa in Praia da Luz, Portugal.

Detectives from Operation Grange — the Metropolitan Police’s probe into her 2007 disappearance — discussed the theory recently with Portuguese police.

Detectives there had previously explored whether Madeleine was searching for her parents, who were at a nearby tapas bar.

She may have been knocked down by a drink driver, they speculated, who put her body in the car and later buried it.

Meanwhile Scotland Yard officers also looked at whether it was a kidnapping or burglary gone wrong.

“A meeting took place recently at the HQ of the General Attorney’s Office, which was attended by the prosecutor from Portimao who is in charge of the Portuguese inquiry,” a source in Portugal said.

“One of the lines of investigation that continues to be pursued is that Maddie could have walked out of the holiday flat herself.”

The Metropolitan Police refused to comment.

PAEDOPHILE THEORY
Another shocking theory that has resurfaced is that Maddie could still be alive imprisoned in a lair and have “no idea” who she is, a former top cop who once searched for her has revealed.

David Edgar, who is convinced Maddie was snatched by a child sex gang, said: “She is most likely being held captive, possibly in an underground cellar or dungeon and could emerge at any time.”

In that unthinkable scenario, she is being kept against her will under a false identity and could even still be in Portugal — where she vanished as a three-year-old in May 2007 — or in neighbouring Spain.

The retired Detective Inspector spoke out after the Home Office announced last week it had granted an extra £150,000 ($264,000) to Scotland Yard to continue searching for the world’s most high profile missing child.

Met Police are chasing up two vital lines of inquiry and have told Maddie’s parents Kate and Gerry they are “hopeful of getting a result.”

Mr Edgar, who passed all his findings to the Operation Grange team when they took over the search in May 2011, said officers could be chasing up two old or new leads.

“Now we’re approaching the 12th year, that’s a significant time but I think she could still be alive and someone is protecting her captors. Someone knows what happened and it’s time they came forward, may be they have and officers are waiting for a confession. It happens.”

Mr Edgar added: “She could literally be anywhere in the world but my hunch is that she is in Portugal. The chance that she may have been smuggled out of the country without being detected is highly unlikely.

“There is someone in Portugal with an open knowledge of where she is and what happened. Someone knows what happened and it’s time they came forward — maybe they already have.”

“Unless a body is found there is hope. Everyone hopes for a positive outcome and Kate and Gerry will never give up, even when the funding runs out. I hope they get an answer they’ve been waiting for so long.”

Mr Edgar believes Maddie — who if alive would now be aged 15 — could be living with her captor in a hideaway home or underground den inland from the popular seaside towns on the Algarve from where she was snatched.

He likened her case to that of kidnapped sex slave Jaycee Lee Dugard who “came back from the dead.”

So far £11.6 million ($A20.5 million) has been spent on the search, with a further £150,000 ($A266,000) released by the Home Office last week.