Prosecutors admit they still cannot prove Christian Brueckner is the man who snatched Madeleine McCann, a friend has claimed.
German authorities are “convinced” the 46-year-old paedophile abducted and murdered the British youngster in Portugal in 2007.
But more than three years since they named Brueckner as their prime suspect, they appear no nearer charging him.
And now the Mirror can reveal a friend claims prosecutors have admitted they are struggling to get enough evidence against him.
They have begun re-interviewing Brueckner’s friends and associates in a bid to crack the case once and for all.
Tragedy as 13-month-old boy dies after the stolen car he was in crashedOne pal, who knew the German when they were living in the Algarve together, spoke to detectives in recent months.
He told the Mirror: “They believe Chris did it, they say they know he did it, but they told me they don’t have proof.
“That’s why they are going back over old interviews. When they spoke to me they were very open about what the situation is.
“It felt like they are struggling. They just asked the same questions again, there was nothing new.”
Another friend, who still lives in the Algarve, was approached before Christmas and asked to go over their statement.
“It was a surprise to hear from them after so long,” said the pal, who asked not to be named.
“They said they wanted to make sure they hadn’t missed anything from the first face-to-face interview.”
Brueckner, who denies any involvement in Madeleine’s disappearance, is currently serving a seven-year jail term for rape.
He was charged last October with five sex crimes allegedly carried out in Portugal between 2000 and 2017.
But the Mirror can reveal a German legal wrangle over jurisdictions is threatening to delay any trial for months.
Outrage as abandoned baby found in pram on beach, with mum off for a coffeeIt could see the Madeleine investigation or the case handed over to new prosecutors.
Prosecutors in Braunschweig have overall charge of the case because Brueckner’s last registered address was in the city in 2016.
But his lawyer Friedrich Fuelscher says he was actually living in a warehouse in Neuwegersleben, Lower Saxony.
He is arguing that prosecutors in that region have jurisdiction and wants the Braunschweig team thrown off the case.
Mr Fuelscher is believed to be preparing a formal application for the case to be transferred to Lower Saxony.
Braunschweig prosecutor Hans-Christian Wolters told the Mirror: “There is no news to report regarding Maddie.
“We are conducting the investigations as we deem appropriate and necessary.”
Asked about the jurisdiction row, he said: “The regional court has not yet made a decision on how and when the proceedings will continue.
“We still assume that we are responsible.
“Should this be judged differently in the context of a judicial review, we would of course have to accept it as such.
“Nothing would be lost as a result, because our files would simply move from one prosecutor’s office to another.”
Mr Wolters said last year that investigators are now working “solely” on the Madeleine probe.
Kate and Gerry McCann, from Rothley, Leics, previously welcomed the investigation and remain hopeful their daughter is still alive.
Their daughter was three-years-old when she vanished from their Praia da Luz holiday apartment in May 2007.
Brueckner is not expected to make any court appearances ahead of his trial at Braunschweig Regional Court.
Prosecutors are waiting on judges to formally indict him on the five sex crimes once they have reviewed the evidence.