EXCLUSIVE: King Charles Quitting Throne! Cancer-Hit Monarch 'Facing Serious Pressure to Abdicate' Over Andrew Windsor's Arrest Shame

RadarOnline.com can reveal King Charles is facing mounting calls to abdicate as pressure intensifies over Andrew Windsor's arrest – with one royal historian warning the cancer-stricken monarch could confront a constitutional crisis if damaging evidence of a palace cover-up emerges.

Charles, 77, who is still undergoing treatment for an undisclosed form of cancer, has come under renewed scrutiny following the arrest on February 19 of his younger brother Andrew, 66, on suspicion of misconduct in public office.

Thames Valley Police confirmed the arrest after officers swooped on Wood Farm on the Sandringham estate before questioning Andrew for nearly 12 hours.

He was released under investigation. The allegations relate to claims that, while serving as a U.K. trade envoy between 2001 and 2011, Andrew shared sensitive information with Jeffrey Epstein.

Andrew has consistently denied wrongdoing.

Royal biographer Andrew Lownie said the monarch must adopt what he described as a "very clear" and decisive stance as the investigation unfolds.

Lownie added: "I do think that King Charles needs to be very clear that he will cooperate and allow his staff to give statements to the police and provide all the internal correspondence, all the complaints that were made about Andrew, all the material the police need to mount a proper investigation."

When asked what might happen if Andrew were not prosecuted but evidence of a palace cover-up surfaced, Lownie said: "Well, I think it's very serious. I think then people will be calling for a clean sweep."

He added: "I don't think William is in any way implicated in this scandal, and I think there will be growing calls for the King to step down."

A senior constitutional scholar said the stakes were unusually high. They added: "If credible evidence emerged that the palace obstructed or concealed material, the pressure on Charles would be immense to step down from the throne early. "Abdication would move from fringe discussion to mainstream debate."

The scholar noted: "The monarchy survives on public trust – any perception of institutional shielding could be explosive."

Charles issued a rare personal statement on the day of Andrew's arrest, referring to him as "Andrew Mountbatten-Windsor" and insisting: "Let me state clearly: the law must take its course."

He pledged his "full and wholehearted support and co-operation" with the investigation but declined to comment further.

Prince William, 43, is widely seen as insulated from the controversy. Lownie distinguished father and son, suggesting the Prince of Wales would not be implicated even if questions were raised about palace conduct during Andrew's time as a working royal.

Online reaction has been sharply divided. One commenter wrote: "It's time for Charles to step down." Others dismissed abdication talk as unrealistic.

One post online read: "There is no cover-up. Leave the dutiful innocent king alone. Vultures."

Another added, "The King will be the King until he stops breathing. William would want that, and it's not like this forever."

A former palace aide said, "There is deep anxiety inside royal circles. Even if Andrew is never charged, the reputational damage is significant. Charles has tried to distance the institution from his brother, but history shows that scandals rarely remain contained."

Andrew remains "under investigation."

His ex-wife, Sarah Ferguson, 66, who spent years sharing his former Royal Lodge mansion home, which Charles has now booted the couple from, is believed to have fled Britain in the wake of her ex-husband's arrest.