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 said an international letter of request was sent to Christian Brückner, ahead of his imminent release for a separate offence, for him to speak with them which he later rejected.

German national Brückner, 49, has never been charged in the McCann case and denies involvement.

Madeleine vanished in the Portuguese resort of Praia da Luz in 2007, shortly after she was left sleeping by her parents, Kate and Gerry McCann, who went for dinner in a nearby restaurant.

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.

He could potentially be released on Wednesday.

Det Ch Insp Mark Cranwell said Brückner remains a suspect in the Met Police’s own investigation into Madeline’s disappearance.

“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.”

Almost two decades since Madeleine’s disappearance, it has become one of the highest-profile unsolved missing person cases in the world.

Earlier this year, German prosecutors pointed to evidence suggesting Brückner may have been in the area when Madeleine disappeared.

Elsewhere in June, Portuguese and German police conducted a fresh search of land in Lagos – between where the McCanns had been staying and addresses linked to Brückner, but this yielded no breakthroughs.

Brückner was not identified as a suspect in her disappearance until 2020.

Due to differences in legal systems, German authorities suspect Brückner of murder in relation to Madeleine, while British police continue to treat her disappearance as a missing persons case.

However, no charges have ever been brought against Brückner in the case of Madeleine, and the full details of the alleged evidence have never been released.