Helge Busching, a former friend of the German drifter, said he was interviewed by Scotland Yard's Madeleine squad for three days after alerting them in 2017.

But he told a court that he first named Christian B to the McCanns' private investigator Dave Edgar in 2008, the year after she disappeared from the family's rented holiday apartment in Portugal.

Mr Edgar told Sky News that he did not recall any message or conversation with Mr Busching and, at the time, had only just been hired by the family and was sifting through many tip-offs.

Mr Busching said when he called Scotland Yard it sent detectives to interview him for three days in Greece where he was living at the time.

During those interviews he told them that Christian B had "confessed" to him he was Madeleine's abductor, claiming "she didn't cry when I took her".

Now, seven years on, he told the court: "I didn't expect the consequences. I've lost my job, my flat and I have no friends. My life has changed negatively."

Mr Busching, a 53-year-old roofer, was giving evidence against Christian B at his trial on sex charges unrelated to the Madeleine case.

The suspect is charged with three rapes and two sex assaults, all allegedly committed over 20 years in Portugal when he was living there on and off.

Christian B, who cannot be fully identified under German privacy laws, denies all the charges and any involvement in Madeleine's disappearance.

Read more on Sky News:
Is the UK preparing for war amid threats of conflict?
Rebel Wilson claims she felt 'sexually harassed' by Sacha Baron Cohen

Two of the rape charges stem from evidence given to police by Mr Bushing, who described his relationship with his former friend: "We were not good friends then and we will certainly never be good friends in the future."

He told the trial in Braunschweig, near Hanover, that Christian B filmed himself raping an elderly woman and a teenage girl two years before the toddler vanished.

Helge Busching, 56, said he saw the date-stamped footage on video tapes he and an associate stole from his friend's home while he was in prison in 2006.

He described how the footage showed a masked man tortured and raped his victims in prolonged assaults before sitting down and removing the mask.

But Christian B's legal team have questioned whether the tapes even existed because they have never been recovered by investigators.

They accused Mr Busching of discrepancies in his evidence which contradicted the version given earlier in the trial by his associate Manfred Seyferth.

The hearing was held up after the defence accused prosecutors of creating worldwide prejudice against Christian B.

His lawyers claimed he could not get a fair trial on rape and sex assault charges because prosecutors had consistently accused him of abducting Madeleine.

Defence lawyer Atilla Ayak asked judges to remove one of the prosecutors in the trial.

Mr Ayak said that in statements, press conferences and media interviews German prosecutors have given the impression that Christian B had killed Madeleine, though he has not been charged in connection with her disappearance and he denies any involvement.

Christian B, 47, is currently halfway through a seven-year jail sentence for raping an elderly American woman in Praia da Luz, the same resort where Madeleine vanished.

Mr Busching has been told to return to give more evidence in June. The sex crimes trial is expected to continue into the summer.