Prince Andrew and Peter Mandelson, the U.K.’s former ambassador to Washington, were arrested within days of each other for investigation into misconduct in public office related to their ties to the late sex offender Jeffrey Epstein. Neither has been charged. Documents released by the U.S. government suggest both had close connections to Epstein and may have shared sensitive information with him.

The arrests have renewed attention to a centuries-old British law that experts say is dangerously vague and urgently in need of reform. Proving misconduct in public office is notoriously difficult, and legal experts say conviction is far from certain despite the high-profile nature of the case.

The arrests and alleged misconduct

Documents released by the U.S. government suggest both men had close ties to Epstein and may have disclosed sensitive information to him during their years in high office.

According to the files, Prince Andrew, known formally as Andrew Mountbatten-Windsor, passed confidential trade reports and other documents to Epstein when serving as the U.K.’s special representative for international trade and investment from 2001 to 2011. In Mandelson’s case, the documents suggest he shared an internal government report with Epstein and promised to lobby for reduced tax on bankers’ bonuses while serving as Business Secretary, approximately 15 years ago.

Both men have previously denied wrongdoing. Police have not disclosed details of how they questioned either individual.

Understanding misconduct in public office

The offense for which both are under investigation is rooted in medieval law and remains ill-defined in modern application.

The Crown Prosecution Service, which conducts criminal investigations in England and Wales, defines misconduct in public office as “serious willful abuse or neglect of the power or responsibilities of the public office held.” The offense carries a maximum sentence of life imprisonment.

Prosecutors must establish that the suspects willfully neglected their duties or committed willful misconduct, that the conduct was so serious it amounts to an abuse of public trust, and that it occurred “without reasonable excuse or justification.”

Why conviction remains uncertain

Legal experts say the offense is notoriously difficult to prosecute, particularly in cases involving senior officials rather than lower-ranking employees.

There is no simple definition of what constitutes a “public officer,” a gap that may complicate the case against Mountbatten-Windsor, whose role as special representative was unpaid and came with paid travel expenses but no regular salary.

Marcus Johnstone, managing director of the law firm PCD Solicitors, said the bar for conviction is “extremely high.” He does not expect either man to be convicted, and estimated that if either were convicted, sentences would likely range from one to ten years in prison.

“Although an investigation is now taking place,” Johnstone said, “we are still a long way away from a potential prosecution.”

The arrests have renewed calls for the law to be overhauled.

The Law Commission, an independent legal body that advises the government on reform, has called for years for the offense to be repealed and replaced with more specific statutes. “The law is in need of reform, in order to ensure that public officials are appropriately held to account for misconduct committed in connection with their official duties,” the commission said on its website.

The commission has also noted that prosecutions under the law have predominantly targeted lower- and mid-ranking officials such as police and prison officers, rather than senior managers or politicians. Cases involving government ministers or trade envoys charged with the offense are “extremely rare,” according to Johnstone.

Both Mountbatten-Windsor and Mandelson were released after police questioning and remain under investigation.