In the U.K., authorities detained four individuals after images of President Donald Trump alongside convicted sex offender Jeffrey Epstein were displayed on Windsor Castle on Tuesday night.

The projections showcased pictures of Trump with Epstein, one including first lady Melania Trump with Epstein and his co-conspirator Ghislaine Maxwell, and a provocative birthday greeting Trump allegedly sent to Epstein in 2003 for a 50th birthday publication.

Trump touched down in London on Tuesday for a state visit, during which he is scheduled to spend Wednesday at the castle with King Charles III, Queen Camilla, and other royals.

Thames Valley Police issued a statement Tuesday night announcing that they charged four adults “on suspicion of malicious communications following a public stunt in Windsor.” They noted that they will proceed with an investigation and that those arrested remain in custody.

“We consider any unauthorized activity around Windsor Castle highly serious. Our officers acted quickly to halt the projection, leading to the arrest of four individuals,” the statement conveyed.

The reference to the supposed birthday message from Trump follows its disclosure by the House Oversight Committee last week after subpoenaing Epstein’s estate for records. Both Trump and the White House strongly refute the message’s legitimacy.

The committee launched an investigation into the Epstein case following uproar after the FBI and Justice Department said over the sumner that they would not release more files linked to the case. The decision sparked outrage by many MAGA supporters — on the campaign trail last year, Trump vowed more transparency in the Epstein case after claiming the government was withholding information.

In addition to subpoenaing the Epstein estate, the committee ordered several high-profile former officials to testify, including former Attorney General Merrick Garland, former Secretary of State Hillary Clinton and former President Bill Clinton.

The Oversight Committee on Tuesday released a transcript of its interview with one such official, former Attorney General Bill Barr, who served during Trump’s first term when Epstein died in jail by suicide in 2019 while awaiting trial on federal sex trafficking charges. In his deposition, Barr said he was not aware of any evidence suggesting that Epstein procured women for Trump.

Trump said in 2019 that he had a falling out with Epstein “a long time ago,” and that he hadn’t spoken with the disgraced financier “for 15 years.” In July, Trump said that their falling out came after Epstein “stole” staff from Trump’s Mar-a-Lago club.

The release of the so-called Epstein birthday book led to the dismissal of U.K. ambassador to the U.S. Peter Mandelson, who was fired last week over his relationship with Epstein. The book purportedly showed a message signed by Mandelson in which called Epstein “my best pal.”

In 2019, the king’s brother, Prince Andrew, stepped back from his royal duties over his friendship with Epstein. Three years later, he was stripped of his military affiliations and royal patronages by Queen Elizabeth II after his lawyers failed to persuade a U.S. judge to dismiss a lawsuit accusing him of sexual abuse.

Epstein survivor Virginia Giuffre had alleged that Andrew sexually abused her when she was 17. He repeatedly denied the allegation but made an an out-of-court settlement with Giuffre. She died by suicide earlier this year.