Suggestions they could be looking into reports child was smuggled over border from Portugal to Spain

Missing: Police are examining possible sightings of Madeleine McCann after she vanished

Scotland Yard detectives flew  to Spain to investigate whether Madeleine McCann was abducted and smuggled across the border from Portugal.

The officers, who visited Barcelona last month, are among  30 Metropolitan Police detectives carrying out a review of her case.

They are also examining possible sightings of Madeleine after she vanished.

She disappeared from a holiday resort in the Algarve in 2007, days before her fourth birthday.

Police are investigating a theory that she may have been snatched by a paedophile gang and smuggled into Spain – an hour’s drive away from her family’s holiday flat in Praia da Luz.

There were a number of sightings of children matching her description in Spain shortly after she disappeared, and Portuguese authorities were criticised for not alerting border and police officials until 12 hours after she went missing.

In July, Scotland Yard said it would examine all the evidence connected to the case, including material gathered by private investigators, after a request by Prime Minister David Cameron

Kate and Gerry McCann seen outside the High Court in London last month where they spoke at the Leveson Inquiry

How Madeleine McCann might look now (left) and with dark brown hair and tanned skin in case she has been living in north Africa (right)

Detectives then spent months reading a huge file of case material that had to be translated from Portuguese to English.

Yesterday police played down any suggestion of a breakthrough

As part of their investigation into the disappearance of the youngster, detectives released this computer-generated image in 2009 of a woman, said to resemble Victoria Beckham

in the case, but Madeleine’s parents Kate and Gerry McCann said they were ‘pleased that the review is making progress’.

A Met police spokesman said: ‘There has been very good co-operation with Portuguese authorities and liaison will continue.

‘Officers have travelled to Portugal three times in connection with the investigative review, and three officers travelled to Barcelona.

They are continuing to discuss how to take it forward and we are hopeful that we will be able to do that.’

Private detectives hired by the McCanns have always believed that a suspicious  incident in Barcelona that  took place three days after Madeleine’s disappearance could be significant.

They made a public appeal for information about a well-dressed woman, said to have an Australian or New Zealand accent and be able to  speak fluent Spanish, who approached some Britons drinking in a bar at 2am.

One man was approached by the woman, who was reportedly  between 30 and 35, in the belief that he was someone she was expecting to meet.

He described her as appearing ‘agitated’