The parents of Madeleine McCann have said they will "never give up hope" of finding their daughter alive as their 13-year long quest to "uncover the truth" of how she went missing following the identification of a new suspect.
In a statement accompanying the revelation that officers had identified a man in connection with her disappearance, Kate and Gerry McCann said: "All we have ever wanted is to find her, uncover the truth and bring those responsible to justice.
"We will never give up hope of finding Madeleine alive, but whatever the outcome may be, we need to know as we need to find peace."
The suspect, a 43-year-old convicted paedophile who has not been named by Scotland Yard, is currently serving a lengthy prison sentence for unrelated offences in Germany.
The country’s Federal Criminal Police Office (BKA) is now leading the investigation. Officers are treating the matter as a murder inquiry.
The suspect, who has been found guilty of a number of crimes including the abuse of children, was living in Portugal at the time of Madeleine's disappearance.
As well as working in catering, the man burgled holiday apartments and hotels, and trafficked drugs.
The three year old disappeared from her bedroom on May 3 2007 during a family holiday in Portugal while her parents were dining with friends nearby in the resort of Praia da Luz - prompting an international manhunt and widespread speculation as to her fate.
Police described Wednesday's appeal - the latest of several issued since her disappearance - as a "significant development".
"You may know, you may be aware of some of the things he has done, he may have confided in you about the disappearance of Madeleine," said senior investigating officer Mark Cranwell.
"More than 13 years have passed, and your loyalties may have changed. This individual is in prison ... now is the time to come forward."
British police said they retained an open mind about the man's involvement and did not have any definitive evidence whether Maddie, who would be 17 today, was alive or not.