Andrew Mountbatten-Windsor has been released from custody almost 12 hours after being arrested by UK Police.
The 66-year-old was detained on suspicion of misconduct in public office.
It reportedly relates to allegations the former Prince shared confidential information with Jeffrey Epstein when he was trade commissioner to the UK.
Despite being released, authorities have confirmed he remains under investigation.
“The arrested man has now been released under investigation” Thames Valley Police said.
“We can also confirm that our searches in Norfolk have now concluded,” the statement said.
Police had been searching a number of residences linked to the disgraced royal, including the Royal Lodge.
King Charles has released a statement expressing his “deepest concern” about the developments.
“I have learned with the deepest concern the news about Andrew Mountbatten-Windsor and suspicion of misconduct in public office,” the King’s statement read.
“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.
“In this, as I have said before, they have our full and wholehearted support and co-operation.
“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.
“Meanwhile, my family and I will continue in our duty and service to you all.
“Charles R.”
