The meeting at the McCanns' house in Rothley, Leicestershire, is understood to have taken place several days before Met Police revealed details about the suspect who is in jail for raping an American pensioner.
The UK officers told them there was no concrete proof that Maddie was dead, despite the fears of the German police.
A family friend said: "It was the conversation they always needed to have but have always feared.
"They were told everything from the points of view of all three forces - British, German and Portuguese. It was a very emotional meeting and lots of tears later shed."
The suspect refuses to co-operate with police and, as yet, they do not have enough evidence to charge him.
A source close to the German police investigation said: "The suspect is saying nothing to officers so Kate and Gerry could be left in limbo for months, which is agonising for them."
It is understood German police were shown photos or video of Maddie's body or given a graphic account of how7
The McCann friend said: "Kate and Gerry wanted to know every single detail no matter how painful and harrowing.
"They have been told everything but sworn to secrecy and were told not to share any news, even with close family."
Madeleine McCann: How police broke news to parents they think Maddie is dead
https://www.express.co.uk/news/world/1292470/Madeleine-mccann-gerry-kate-mccann-british-police