London - British detectives investigating the 2007 disappearance of Madeleine McCann in Portugal on Monday published two new electronic images of a man they want to contact in a major appeal which will also be shown in Germany and the Netherlands.
Police said the man is of "vital importance" and the two images have been drawn up based on statements and descriptions from two different witnesses who saw the man in the area of Praia da Luz town.
A prime-time British television programme will also present a fresh timeline of events surrounding the disappearance of the British girl from her family's holiday apartment in the Portuguese resort just a few days before her fourth birthday.
The witnesses described the man in the e-fit as being white, aged between 20-40 years old, with short brown hair, of medium build, medium height and clean shaven.
One of the images shows him with a fuller jaw than the other.
Portuguese authorities closed their investigation in 2008, but London's Metropolitan Police spent two years reviewing the evidence and opened their own probe in July this year.
"Whilst this man may or may not be the key to unlocking this investigation, tracing and speaking to him is of vital importance to us," said Detective Chief Inspector Andy Redwood, Scotland Yard's senior investigating officer in the case.
"We have witnesses placing him in the resort area around the time of Madeleine's disappearance."
Praia da Luz is a "popular holiday destination for many nationalities", Redwood said, adding that he would be travelling to the Netherlands, Germany and Ireland "to seek the support of the public there".
The Crime-watch show will include a new 25-minute reconstruction as well as live interviews with Gerry and Kate McCann, who launched a global media campaign to find their daughter and still hold out hope she is alive.
Police said at the weekend that the timeline around the incident had also significantly changed, with further details to be released during the show.
Ahead of the broadcast Madeleine's parents told the BBC of the pain they still feel.
"When it's a special occasion, when you should be at your happiest, and Madeleine's not there, that's when it really hits home," Gerry McCann said.
"Obviously, Madeleine's birthday goes without saying."
Kate McCann added: "It's when you have big family occasions really. That's it, isn't it? 'Family occasion' and you haven't got your complete family."