Mandelson police probe risks collapse as US blocks access to key Epstein files

But neither the DoJ nor the FBI has replied to the Met’s request for the documents.

The request was initially made through an informal information-sharing arrangement between the agencies.

After receiving no response, the Met escalated the matter via a formal Mutual Legal Assistance process - but this route could take years to yield results.

The investigation now risks being abandoned altogether, according to The Telegraph.

Lord Mandelson quit the Labour Party and left the House of Lords in February after the released files appeared to show he had leaked information to Epstein while serving as a minister under Gordon Brown.

The scandal played a role in bringing Sir Keir Starmer’s time as Prime Minister to an end.

The peer was placed under criminal investigation after the documents suggested he passed market-sensitive material to Epstein during the 2008 financial crisis.

He has never faced charges and denies all wrongdoing.

His arrest came after Sir Lindsay Hoyle, the Commons Speaker, tipped off police that Lord Mandelson was planning to travel to the British Virgin Islands.

Lord Mandelson’s legal team dismissed that claim as without foundation.

He has in the past expressed regret over his friendship with Epstein and apologised to the convicted paedophile’s victims.

Prosecuting misconduct in public office is notoriously difficult and typically demands extensive documentary evidence.

Lord Mandelson’s lawyers could argue that the partially redacted emails published online lack context and do not paint the complete picture.

Officers fear that relying on incomplete versions of the files in court would leave their case open to challenge.

The Telegraph reports that the deadlock has partly arisen because the US administration is wary of releasing material that could harm Donald Trump’s reputation.

If authorities did share the files, it could create a precedent for other cases that might reignite the wider Epstein scandal.

Mr Trump was forced to release nearly 3.5 million pages of Epstein-related documents in January after months of pressure, with the release raising questions about his own ties to the financier.

Donald Trump and Jeffrey Epstein were friends until a falling out in the 2000s 

The Met hopes to build its case through interviews with former politicians and officials who served alongside Lord Mandelson in government, but sources said securing enough evidence without the full Epstein files would be virtually impossible.

A DoJ spokesman said: "The Department of Justice has not refused to assist any jurisdiction investigating potential criminal conduct related to Jeffrey Epstein."

"Both US and UK authorities follow established and legally required procedures for sharing information and evidence, and those processes ensure that any co-operation adheres to applicable laws that govern international evidence sharing and protects the integrity of ongoing matters," the spokesman added.

"The department remains committed to co-operating with all jurisdictions pursuing potential crimes and will continue to do so in accordance with federal law and longstanding practice."