Image copyright PA Image caption Madeleine McCann was three when she went missing in 2007

The number of UK officers investigating the disappearance of Madeleine McCann has been cut from 29 to four, the Metropolitan Police says.

The Met said the "vast majority" of the work in its inquiry into Madeleine's disappearance had been completed.

It said no conclusion had been reached but it was now following a "small number of focused lines of inquiry" which was why the team had been cut.

Madeleine's parents said they "fully understand" the decision.

Media playback is unsupported on your device Media caption Spokesman for the McCann family Clarence Mitchell says the the case into her disappearance is not drawing to a close

They said they remained "hopeful" their daughter would be found.

Madeleine, from Rothley in Leicestershire, was three years old when she went missing from her family's holiday apartment at the Ocean Club in Praia da Luz on 3 May 2007.

'Exceptional case'

Assistant Commissioner Mark Rowley, from the Met, said: "The Met was asked to take on this exceptional case as one of national interest.

"We were happy to bring our expertise to bear only on the basis that it would not detract from the policing of London; and the Home Office have additionally funded the investigation above normal grants to the Met.

"That will continue at the reduced level."

Thursday 3 May 2007: Timeline

20:30 Kate and Gerry McCann leave their apartment to have dinner at a Tapas bar

Kate and Gerry McCann leave their apartment to have dinner at a Tapas bar 21:05 Gerry McCann checks on Madeleine and her siblings

Gerry McCann checks on Madeleine and her siblings 22:00 A man is seen carrying a child wearing pyjamas heading towards the ocean

A man is seen carrying a child wearing pyjamas heading towards the ocean 22:00 Kate McCann raises the alarm that Madeleine has gone missing

Clickable map and timeline

Madeleine's parents Gerry and Kate McCann praised the "meticulous and painstaking work" done by police.

They said: "We are reassured that the investigation to find Madeleine has been significantly progressed and the Met has a much clearer picture of the events in Praia da Luz leading up to Madeleine's abduction in 2007.

"Given that the review phase of the investigation is essentially completed, we fully understand the reasons why the team is being reduced.

"We would also like to thank the Home Office for continuing to support the investigation.

"Whilst we do not know what happened to Madeleine, we remain hopeful that she may still be found given the ongoing lines of inquiry."

'Far from disillusioned'

Detectives from the Met began working through material and following lines of inquiry after the Home Office requested a review of the case in May 2011.

Operation Grange, which has been supporting the Portuguese police's investigation, became a full investigation in July 2012.

Officers have now finished bringing together and investigating the information held by Portuguese police, the UK investigation and the private investigators working on behalf of the McCann family, the Met said.

Met investigation 1,338 statements taken 1,027 exhibits collected 60 persons of interest investigated

8,685 potential sightings considered

560 lines of inquiry identified

30 requests made to other countries asking for work to be carried out

The force said the inquiry had taken 1,338 statements and collected 1,027 exhibits but had not reached a conclusion yet.

'Near future'

Image copyright Reuters Image caption Gerry and Kate McCann said they remained hopeful their daughter would be found

Clarence Mitchell, spokesman for the McCanns, said: "Kate and Gerry are far from disillusioned. This is no way the end of Operation Grange.

"If anything it will now continue on a newly-focused, smaller yes, but focused basis that will hopefully lead to Madeleine being found somewhere in the near future."

Officers have investigated more than 60 persons of interest, the Met said, adding that a total of 650 sex offenders had also been considered as well as reports of 8,685 potential sightings of Madeleine around the world.

Having reviewed all of the documents, "7,154 actions were raised and 560 lines of inquiry identified", the Met said.

It said more than 30 requests had been made to "countries across the world asking for work to be undertaken on behalf of the Met".