Officers investigating the Madeleine McCann case have received new information that could be "vital."
It comes as new information has been revealed with prime suspect Christian Brueckner appearing before court last week facing the charges of three rapes and two sex assaults.
Brueckner has not been charged relating the Madeleine McCann case.
However, detectives hope his appearance in court will continue to generate even more information in the days ahead.
Christian Brueckner is the main suspect in the disappearance of the toddler
Getty/PA
A source told The Sun: "New information has been coming in ever since Brueckner appeared in court last week. It’s a massive boost for German detectives because their investigation had really hit a bit of a brick wall.
"So they are really pleased about this, and really hope this will give fresh impetus to the investigation into what happened to Madeleine.
"They remain convinced Christian Brueckner was either involved in Maddie’s disappearance or knows about how Maddie vanished.
"Having his face on TV screens, and in newspapers across the world, has generated fresh calls, tip-offs and leads which they will look into and which they hope could prove vital."
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The apartment at the Ocean Club Hotel in Luz, Portugal where Madeleine McCann went missing
PA
However, there is still some doubt about what Brueckner was doing at the time of Maddie's disappearance on May 3, 2007. Her whereabouts remain unknown although German prosecutors believe she is dead.
The source added: "The timeline of where Christian Brueckner was and when during that period is still far from clear.
"He was living a nomadic lifestyle. He was a drifter going from here to there and he would have come into contact with a lot of people. The police are convinced many of them may not yet have come forward.
"The publicity around this case could prompt someone who knows something into doing just that. This is what the German cops are now hoping for."
The German is currently serving a seven-year prison term for rape and drug trafficking. There is some suspicion that he has changed his appearance since the time of Maddie's disappearance.
The source added: "The Christian Brueckner of today is not the same person he was back in 2007 when Maddie disappeared. German detectives are convinced he looks very, very different and has blown tens of thousands of pounds changing the way he looks.
“For a long time, Christian Brueckner was a prolific drug dealer who earned a lot of money and lived a very nice lifestyle. He had the means to have surgery and to make changes to the way he looked. Officers think there’s every chance the way he looks now is an illusion to the man he was 10, 15 years ago.
"They’ve always been concerned that this is a key area cops in the Algarve failed to properly grip or investigate fully from day one. So it’s an area they will be focusing on a lot more in the months ahead."