Suggestions they could be looking into reports the three-year-old was abducted and smuggled over the border to Spain

Detectives investigating the disappearance of Madeleine McCann have flown to Spain as part of a review into the case.

Two officers from Scotland Yard travelled to Barcelona two weeks ago to liaise with officers as part of a review of the whole investigation.

They would not confirm their specific reasons for travelling to the city, however it is thought they might be looking into reports the three-year-old was abducted and smuggled over the border to Spain.

Two officers from Scotland Yard travelled to Barcelona in the last two weeks to liaise with officers as part of a review of the disappearance of Madeleine

This morning Clarence Mitchell, the McCann's spokesman told MailOnline: 'Kate and Gerry welcome the on-going work by the Metropolitan Police and they are pleased that the investigative review is making progress.'

The trip is part of the Met Police's 'investigative review' into all the work done since the investigation into the missing three-year-old began.

It was ordered by Prime Minister David Cameron and Home Secretary Theresa May in May last year.

As part of the review detectives have also travelled to Portugal three times to speak with officers who worked on the original investigation.

They also spent the first five months reading all the information from the case file which had to be translated from Portuguese to English.

Kate McCann and Gerry McCann arrive at the High Court in London to give evidence to the Leveson Inquiry last month

There are no suggestions of any major breakthroughs in the case.

The Evening Standard said officers could be investigating one theory that the toddler was abducted by a paedophile gang and smuggled over the border to Spain either in a vehicle or by boat.

Detectives released this computer generated image of a woman, said to resemble Victoria Beckham in2009

There were sightings of a girl matching Madeleine's appearance in Spain shortly after she vanished and Portuguese authorities were criticised for not informing border officials for 12 hours after they first knew she was missing.

In September 2009 the McCann's received 1,000 reports following an appeal over a Victoria Beckham lookalike seen in Barcelona who they thought may be connected to the disappearance of their daughter.

Investigators wanted to trace the woman, said to have been acting suspiciously, who asked a witness at a Barcelona marina if he was there to deliver her 'new daughter' on May 7 2007.

The well-dressed woman was described as possibly having an Australian accent and appeared agitated.

Madeline, from Rothley, Leicestershire, vanished from Portuguese holiday resort Praia da Luz in the Algarve four years ago. She was asleep in the family's holiday apartment with her brother Sean and sister Amelie when she vanished on May 3 2007 shortly before her fourth birthday.

Her parents Gerry and Kate McCann, both doctors, were eating at a nearby tapas restaurant with friends at the time.

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)

A Met Police spokesman said two officers had travelled to Portugal three times for the investigative review and two officers travelled to the Spanish city between November 23 and 25.

He would not reveal any further details but added: 'The investigative review is on-going.'  

The official Portuguese and Leicestershire police investigation into Madeleine's disappearance ended in July 2008. However private detectives working for the McCann's have been working to trace her ever since.