During a public appearance to a cathedral in Staffordshire on Monday, the King was confronted by a man who asked him about Prince Andrew's relationship with disgraced financier Epstein.
The individual asked how long the monarch had been known about his sibling's relationship with Epstein, and also raised doubts about whether he had instructed the authorities to "hide" for Prince Andrew.
Amid the heckling, there were crowds of well-wishers and applause for the monarch, who was in Staffordshire for an ceremony.
Prince Andrew's connections with Epstein have been under intense scrutiny in recent weeks. The prince, who gave up his royal duties earlier this month, has repeatedly denied any misconduct.
"For how long have you been aware about Prince Andrew and Jeffrey Epstein? Have you asked the authorities to conceal for him?"
The monarch remained silent but continued greeting supporters, some of whom chanted "God Save The King". One supporter can be overheard requesting him for a hug.
Another woman outside the venue was also observed telling the protester to "leave" and to "shut up".
The controversy over the Duke of York's connections to Jeffrey Epstein has been reignited by misconduct allegations repeated in Virginia Giuffre's recently released book.
In the memoir, Ms Giuffre claims she had sexual encounters with the royal on three separate occasions, including one instance with Jeffrey Epstein and "eight other young girls"
Andrew, who reached a out-of-court agreement with Ms Giuffre in recent years, has consistently denied any misconduct. In 2019, he told BBC Newsnight he did not remember meeting Ms Giuffre "at all", and that they "never had any sort of intimate relations."
But recently, new inquiries have been asked about how he is able to fund his way of life despite not being a working royal.
The revelation that he has only ever paid a nominal fee on his Windsor mansion has heightened the examination over his living arrangements - even though he made large payments initially, including for renovations.
The political party said he should be called in front of MPs to give testimony about his rental agreement of his lodge.
But last Thursday, the authorities refused to give MPs time to debate the prince's titles or his residence, despite growing pressure for investigation.
The royal household has not commented on whether Prince Andrew might move out of his current residence - or where he might go.
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