The release of files related to Jeffrey Epstein produced their most high-profile political casualty yet in the arrest Thursday of Andrew Mountbatten-Windsor, sending shock waves across Europe and rocking Britain’s political establishment. 

The former Prince Andrew was formally arrested by officers from the Thames Valley Police on suspicion of misconduct in public office, charges sparked by Mountbatten-Windsor’s connection to Epstein, the deceased financier and sex-crime offender.

Police have reportedly said they were reviewing allegations that Epstein trafficked a young woman to the U.K. specifically for a sexual encounter with Mountbatten-Windsor, who in turn provided Epstein with classified information Mountbatten-Windsor had from his role as the U.K.’s trade envoy.

Reports said Mountbatten-Windsor was questioned for several hours before being released Thursday. The arrest came on the former royal’s 66th birthday. According to news reports quoting legal analysts, the defendant could face life in prison if convicted.

King Charles III did not defend his younger brother, saying that “the law must take its course.” Reports said Buckingham Palace had not been informed in advance of the arrest. 

After addressing the arrest briefly in London, Charles said he would have no further comments on the topic.

“As this process continues, it would not be right for me to comment further on the matter,” he said.

The widening scandal has expanded beyond the British royal family to implicate Peter Mandelson, who served for seven months last year as the U.K.’s ambassador to the U.S., appointed by Prime Minister Keir Starmer. Earlier this month, Mandelson, 72, resigned from the House of Lords in connection to allegations he shared privileged information with Epstein.

Mandelson’s role sparked calls for Starmer to resign, including from within his own party, where Scottish Labour Party Leader Anas Sarwar said Starmer showed “terrible judgment” by appointing Mandelson to his ambassadorship despite knowing he and Epstein had a close relationship. 

“This distraction needs to end and the leadership in Downing Street has to change,” Sarwar said. “There have been too many mistakes.”

Harriet Harman, a former deputy leader of the Labour Party, said recent developments made Starmer look “weak, naïve, and gullible.”

For his part, Starmer denied knowing about the extent of the ties between Mandelson and Epstein, apologizing publicly only for “having believed Mandelson’s lies.” 

So far, Mandelson has not been arrested or charged, and he does not appear to face any allegations of sexual misconduct. But there is an open investigation into whether the former ambassador’s misconduct was enough to amount to “misconduct in public office,” a serious offense.

Senior party figures aside from Sarwar and Harman have stood by the prime minister, though news reports in the U.K. said Starmer’s grip on power had clearly been weakened by the scandal. Opinion polls show his approval levels have eroded and the developments have given new strength to political opposition leaders. 

Even weeks prior to Andrew's arrest, 75% of Britons had an unfavorable opinion of the prime minister, according to a YouGov.co.UK opinion poll. 

Several key Starmer administration officials have resigned, including Chief of Staff Morgan McSweeney, who took the blame for Mandelson’s connection to Starmer.

“I advised the prime minister to make that appointment, and I take full responsibility for that advice,” McSweeney said.