King Charles III is speaking out after British police arrested his brother, the former Prince Andrew, on Thursday.
Andrew -- who now goes by Andrew Mountbatten-Windsor after his "prince" title was revoked by his brother last year -- was arrested on suspicion of misconduct in public office stemming from his time as a U.K. trade envoy, a role in which he was responsible for promoting British business interests abroad.
The arrest comes in the wake of the U.S. Justice Department's release of a tranche of documents related to the late convicted sex offender Jeffrey Epstein, with whom Andrew appears to have communicated both directly and indirectly through his aides.
Charles released a statement on Thursday saying he had "learned with the deepest concern" about Andrew's arrest.
"What now follows is the full, fair and proper process by which this issue is investigated in the appropriate manner and by the appropriate authorities," Charles said. "In this, as I have said before, they have our full and wholehearted support and co-operation."
He continued, "Let me state clearly: the law must take its course. As this process continues, it would not be right for me to comment further on this matter."
Charles added that the royal family would continue to fulfill its duties and service to the British public in the meantime.
The palace confirmed to ABC News that they were not informed about Andrew's arrest ahead of time.
Thames Valley Police said in a statement Thursday that they had "arrested a man in his sixties from Norfolk on suspicion of misconduct in public office and are carrying out searches at addresses in Berkshire and Norfolk."
"The man remains in police custody at this time. We will not be naming the arrested man, as per national guidance," the police statement added.
Charles released a separate statement last week addressing Andrew's alleged ties to Epstein, who died by suicide in a New York City jail cell in 2019, as detailed in the Justice Department documents.
Andrew has previously denied wrongdoing with respect to Epstein.
"The King has made clear, in words and through unprecedented actions, his profound concern at allegations which continue to come to light in respect of Mr Mountbatten-Windsor's conduct. While the specific claims in question are for Mr Mountbatten-Windsor to address, if we are approached by Thames Valley Police we stand ready to support them as you would expect," a Buckingham Palace spokesperson said in a statement to ABC News on Feb. 9, referring to the U.K. police department assessing the allegations.
Meanwhile, the royal family continued with their official engagements Thursday, Queen Camilla visiting Sinfonia Smith Square Hall in London, where she heard a lunchtime orchestral performance, and Charles attending Tolu Coker's London Fashion Week show at 180 Strand.
Prince William, the heir to the British throne, and his wife Kate, the Princess of Wales, are not expected to issue a separate statement, but they support the king's statement, ABC News understands.
Earlier this month, on Feb. 9, Kensington Palace released its first-ever statement about Andrew on behalf of William and Kate, which read, "I can confirm The Prince and Princess have been deeply concerned by the continuing revelations. Their thoughts remain focused on the victims."
