Portuguese police say they are 'completely in tune' with British detectives following a tip that a gang of European traffickers snatched Madeleine McCann.

Policia Judiciaria bosses say their relationship with the Scotland Yard team given fresh cash to investigate the new lead is 'easy and fluid.'

The comments, made by a Lisbon-based senior officer, will give missing Madeleine's parents fresh hope of answers to the near ten-year-old mystery.

The PJ made no secret of their rejection of the theory championed by former Operation Grange chief Andy Redwood about Madeleine being kidnapped from her Algarve holiday flat by a gang of thieves during a bungled burglary in May, 2007.

Detectives will work on the assumption that Maddie (pictured) was snatched by a gang of European traffickers

Kate and Gerry McCann hold a news conference in 2012 to mark the 5th anniversary of the disappearance of their daughter Madeleine

Before this weekend's trafficking revelations, it was thought the botched burglary claims formed the final line of inquiry.

But Portugal's Attorney General's office confirmed today the last of six 'letters of request' Portuguese police based in the Algarve city of Faro had been asked to work on, was completed and sent back on October 25.

Officers in Faro had been expecting to receive a new letter asking them to arrange a fresh interrogation of four locals questioned as 'arguidos' or official suspects in July 2014 as part of the botched burglary theory - but so far none has been forthcoming.

The Operation Grange team, now led by DCI Nicola Wall, is in regular contact with the Madeleine McCann review team based in Porto which got the case reopened in Portugal in October 2013 after linking convicted burglar Euclides Monteiro who died in a tractor accident in 2009 to the Brit child's disappearance.

A senior Lisbon-based PJ officer, speaking on condition of anonymity, said: 'Although we are talking from a formal point of view about two different investigations which are independent of each other, the contacts between the two teams are easy and frequent.

'The high-ranking meetings at the PJ HQ in Lisbon, which worked to establish models of co-operation are no longer needed.

A police officer and sniffer dog search scrubland for missing British girl Madeleine McCann during a previous investigation in Praia da Luz, Algarve

'Since the Operation Grange leadership changed, the relationship is easy and fluid and conducted by phone.

'There is still work to do. Not all possibilities have been dismissed. There is one line of investigation to be explored and we and Scotland Yard are completely in tune with each other.

'We are both working on the same line of investigation and are in close contact.'

Weekend reports said the Scotland Yard search for Madeleine had been extended by months after detectives were given more cash.

The Met was said to be taking the development about a gang of European traffickers snatching the youngster so seriously that leading Whitehall officials were being briefed on its progress.

The investigation of the new lead was described as 'the last throw of the dice.'

In July 2014 four Portuguese men faced a barrage of more than 250 questions while being questioned as arguidos or formal suspects in interviews conducted at Scotland Yard's request.

Scotland Yard is set to investigate an 'important' new lead in the disappearance of Madeleine McCann

They included the question: 'Did you kill Madeleine?' All four men denied any involvement in Madeleine's disappearance.

They were quizzed after British detectives honed in on the theory Madeleine, three when she disappeared on May 3 2007 from her holiday apartment in Praia da Luz as her parents ate tapas nearby, may have killed during a bungled break-in and her body buried on waste ground nearby.

Eleven witnesses including several Brits were questioned in December 2014 at the same police station in Faro.

Portuguese police privately dismissed the botched burglary theory and indicated at the time they believed Madeleine had been snatched by a foreigner no longer in Portugal, although they didn't rule out the involvement of Euclides Monteiro, a former worker at the Ocean Club where the McCanns stayed.

The Policia Judiciaria declined today to make any official comment on the weekend trafficking claims, which came eight months after Met commissioner Sir Bernard Hogan-Howe predicted the force's £12 million Operation Grange probe was coming to an end.

The 'arguido' status of the four men questioned in July 2014 was lifted under Portuguese law when the rogatory letter relating to the questioning was returned.

A spokesman for Portugual's Attorney General's office confirmed today the first of the six letters was returned on November 26 2014 after being completed.

The remaining five were returned between January 12 last year and October 25 this year, when the final one which is thought to have contained the results of DNA tests from Portugal's Police Scientific Laboratory, was sent back to the British authorities.

The content of the letters has not been made public.

A Faro police source said the PJ team there had been expecting to receive a new letter after Operation Grange officers signalled they believed the 253 questions they wanted asked of the arguidos and witnesses hadn't been put to them in all cases.

Detectives have explored dozens of theories since she vanished, including allegations she was kidnapped by a paedophile gang or snatched and sold by child traffickers

He said: 'We maintained regular email correspondence with the team but reached a point where they kept saying 'We are re-evaluating our investigation.'

'As they expressed the need for further questioning, we have been expecting a new rogatory letter, but it never arrived'

'The last letter of request was answered, once we received the remaining requested results.

'That was our task, to answer the letters of request about everything requested and allowed by Portuguese law.

'Now, we have no more contact with the British authorities unless something new is requested, which hasn't happened yet'.

The child trafficking theory was first raised in late 2007 by private detectives who believed there could have been gang 'spotters' working in Praia da Luz.