The prime suspect in the high-profile case of Madeleine McCann's disappearance has declined to be interviewed by the Metropolitan Police, the force has said.
The Met stated that an international letter of request was sent to Christian Brückner, before his anticipated release for an unrelated offence, which he later rejected.
German national Brückner, 49, has never been charged with any crime in relation to the McCann case and denies any involvement.
Madeleine vanished in the Portuguese resort of Praia da Luz in 2007. She and her siblings had been left sleeping in a holiday apartment while her parents, Kate and Gerry, went for dinner at a nearby restaurant.
They had checked in on the children periodically until Kate discovered Madeleine was missing at around 22:00.
Brückner is currently serving a seven-year prison sentence in Germany for the rape of an elderly 72-year-old woman at her home in Praia da Luz in 2005.
German authorities have stated he will be released by Wednesday.
Det Ch Insp Mark Cranwell said Brückner remains a suspect in the Met Police's own investigation into Madeleine's disappearance. He has been the prime suspect in the German and Portuguese investigations since 2020 and 2022, respectively.
We have requested an interview with this German suspect but, for legal reasons, this can only be done via an International Letter of Request which has been submitted, Det Ch Insp Cranwell said.
It was subsequently refused by the suspect. In the absence of an interview, we will nevertheless continue to pursue any viable lines of inquiry.
We can provide no further information while the investigation is ongoing.
Madeleine's disappearance has become one of the highest-profile unsolved missing person cases in the world.
German prosecutors have indicated with evidence—including mobile phone data—that Brückner may have been in the area when she vanished, and they consistently assert that they believe he is responsible.
However, they have not found strong enough evidence to lay charges.
Brückner, who spent many years in the Algarve, was a drifter, a petty criminal, and a convicted sex offender. He has been previously convicted for sexually abusing children in 1994 and 2016.
Portuguese and German police carried out a fresh search between where the McCanns had been staying and addresses linked to Brückner in June this year, but this yielded no breakthroughs.
In 2023, investigators carried out searches near the Barragem do Arade reservoir, about 30 miles from Praia da Luz. Brückner spent time in the Praia da Luz area between 2000 and 2017 and had photographs and videos of himself near the reservoir.
In October last year, Brückner was cleared of unrelated sexual offences by a German court, alleged to have taken place in Portugal between 2000 and 2017.
Due to differences in legal systems, German authorities suspect Brückner of murder in relation to Madeleine McCann, while British police continue to treat her disappearance as a missing persons case.
The funding given to the Met's investigation, Operation Grange, has exceeded £13.2 million since 2011, with a further £108,000 secured from the government in April.
