Detectives reviewing the disappearance of Madeleine McCann have identified at least "a handful of people of interest" in connection with the case, Scotland Yard has confirmed.

Madeleine, then nearly four, disappeared from her family's holiday apartment in Praia da Luz in Portugal's Algarve on 3 May 2007.

Detective Chief Superintendent Hamish Campbell said the people could be investigated further, if only to be eliminated as people of interest.

He said: "The purpose of the review was to look at the case with fresh eyes and there is always real benefit in doing so."

The review has further identified both investigative and forensic opportunities to support the Portuguese police.

"There is more than a handful of people of interest which could be explored further if only to be eliminated.

"The key things are to investigate the case and our work is happening to support the Portuguese," he said.

The girl's parents Kate and Gerry McCann say they remain hopeful as ever as Operation Grange continues, and that police seemed "more determined than ever".

"In many ways things haven't changed and you could argue that, with the Met review two years in, we are actually in a better place because so much more information has been collated and lots of pieces of the jigsaw have been filled," said Mr McCann.

The couple's hope was further reinforced by the recent discovery of Amanda Berry, Gina DeJesus and Michelle Knight in Ohio, a decade after they went missing in separate incidents.

When the women were found, the McCanns said the rescue of the women "reaffirmed" their hope of finding their daughter, which had never diminished.

"Their recovery is also further evidence that children are sometimes abducted and kept for long periods," they said in a statement.

"So we ask the public to remain vigilant in the ongoing search for Madeleine."