The criminal investigation into whether Peter Mandelson passed confidential British government information to Jeffrey Epstein is facing a potentially decisive evidential problem because Scotland Yard has yet to obtain the original, unredacted U.S. records on which some of the allegations are based.

Detectives have escalated their request through the formal legal-assistance process between Britain and the United States, but police sources fear that a prolonged delay could make it substantially harder to build a case capable of supporting criminal charges.

The Metropolitan Police has not announced that the investigation is being abandoned and continues to treat it as an active inquiry.

The difficulty is not simply that investigators want to see more material.

Documents publicly released by the U.S. Department of Justice have been redacted and, in some cases, presented as copies rather than the original electronic records.

If prosecutors sought to rely on emails in court, Mandelson's lawyers could require the prosecution to establish their authenticity, provenance and full context.

Original electronic records can contain metadata and other information that helps establish when a message was created, transmitted or received and whether the version being relied upon is complete.

Without that underlying evidence, a defence challenge to the documents could become significantly more difficult for prosecutors to overcome.

Mandelson was arrested at his London home on February 23 on suspicion of misconduct in public office and was released after questioning.

His bail conditions were removed in March after police concluded that he was not considered a flight risk, but the investigation itself continued.

He has not been charged with any offence and denies wrongdoing.

The inquiry began after millions of Epstein-related documents released by the U.S. Justice Department appeared to show Mandelson sharing internal government information with Epstein while serving as business secretary under Prime Minister Gordon Brown.

The material included communications concerning government discussions during and after the global financial crisis, some of which appeared to involve market-sensitive information.

The Metropolitan Police formally opened an investigation in February into whether the disclosure of such information could amount to misconduct in public office.

Misconduct in public office is a common-law offence with a deliberately high legal threshold.

Prosecutors must establish that a public official, acting in that capacity, wilfully neglected a duty or committed misconduct so serious that it amounted to an abuse of the public's trust, without reasonable excuse or justification.

That makes documentary evidence concerning what information was passed, its sensitivity, Mandelson's official responsibilities and the circumstances of each disclosure particularly important.

British investigators initially sought access to the unredacted Epstein material through informal law-enforcement contacts.

Those attempts did not produce the records they wanted, and the Metropolitan Police subsequently made a formal mutual legal assistance request.

Britain and the United States have a longstanding treaty framework for exchanging evidence in criminal investigations, but formal requests can involve legal review, privacy restrictions, court orders and other procedural requirements.

Police sources now fear that the process could take long enough to weaken the practical prospects of a prosecution.

The U.S. Justice Department disputes any suggestion that it has refused to cooperate.

It says it has not refused assistance to jurisdictions investigating potential Epstein-related crimes and that both British and American authorities must follow legally required procedures governing the international transfer of evidence.

The department says those rules are intended to protect ongoing investigations, victims and the integrity of legal proceedings.

Its public release of Epstein material already totals about 3.5 million pages, alongside thousands of videos and images, although significant portions of the underlying files remain subject to redactions or legal restrictions.

There is a more politically sensitive allegation surrounding the delay.

People familiar with the British investigation have suggested that figures in the Trump administration may be reluctant to facilitate broader disclosure because additional Epstein material could revive scrutiny of President Donald Trump's past association with Epstein or create a precedent for demands from other investigators.

That explanation has not been established as fact.

The Justice Department rejects the suggestion that it is withholding assistance for political reasons and says cooperation will proceed in accordance with federal law.

Mandelson's relationship with Epstein has already produced extraordinary political consequences in Britain.

He was dismissed as Britain's ambassador to Washington in September 2025 after further evidence emerged about the extent of their relationship.

He left the Labour Party and resigned from the House of Lords in February as additional Epstein documents became public.

The controversy over his appointment, including the later disclosure that security vetting had raised serious concerns, became one of the most damaging episodes of Keir Starmer's premiership and contributed to the loss of confidence that preceded Starmer's decision to resign in June.

Starmer formally left Downing Street on July 20 and was succeeded by Andy Burnham.

Detectives are continuing to seek evidence inside Britain, including testimony and records from former ministers, officials and others who worked with Mandelson during Gordon Brown's government.

That means the U.S. files are not necessarily the only route to a prosecution.

But investigators believe access to the original Epstein records could determine whether the evidence ultimately reaches the standard required for the Crown Prosecution Service to authorise charges.

For now, Mandelson remains under investigation, uncharged and denying wrongdoing, while the formal British request for the American evidence remains unresolved.