Detectives are targeting 12 British potential suspects as they launch a new investigation into the disappearance of Madeleine McCann.

A Metropolitan Police team says they are among 38 "persons of interest" in the case and they are working on the assumption that Madeleine - aged three when she went missing in 2007 - may still be alive.

Officers have completed a two year review of the stalled Portuguese inquiry and say they are moving to an "investigative stage".

They now intend to pursue further information on the dozens of individuals they want to speak to over the suspected abduction of Madeleine from her family's holiday villa in Praia da Luz.

Kate and Gerry McCann said they "warmly welcome" the latest development in the search for their missing daughter.

John O'Connor, a former Commander of the Scotland Yard flying squad, spoke to Newstalk's Breakfast:

The Met intends to apply to issue formal requests to Portugal for evidence to be gathered and to allow a team of British officers to be present during the process.

The working relationship between UK and Portuguese police is now said to be "positive and focused" after previous attempts at cooperation faltered amid intense interest in the case.

An age-progressed photo of Madeleine McCann

Detective Chief Inspector Andy Redwood, who is heading up the inquiry, calls this "a critical moment" in the the search for Madeleine.

DCI Redwood added: "There is no clear, definitive proof that Madeleine McCann is dead. On that basis I genuinely believe there is a possibility she is still alive. And so I would like to ask the public to continue to look for her."

Madeleine vanished from her bedroom in the Portuguese resort in May 2007 as her parents dined with friends nearby.

The local police investigation was called off a year later, yielding few clues into her disappearance or whereabouts.