Prince William was heckled in Cornwall over his uncle, Andrew Mountbatten-Windsor, and the scandal surrounding him.
A man was heard asking William about Andrew as the future king interacted with royal fans who had gathered to greet him.
This comes days after Andrew was arrested on suspicion of misconduct in public office. Although the younger brother of the British monarch was released after hours of interrogation, authorities said he still remains under investigation.
Following his brother's arrest, King Charles issued a statement, voicing support for the authorities. "The law must take its course, " said the king while assuring the nation that his family stand by the investigating authorities.
The king stripped Andrew of his remaining royal titles and evicted him from Royal Lodge in Windsor over his links to the late sex offender Jeffrey Epstein in October last year.