Andrew Mountbatten-Windsor has been "released under investigation"

The statement reads: "Thames Valley Police is able to provide an update in relation to an investigation into the offence of misconduct in public office.

"On Thursday we arrested a man in his sixties from Norfolk on suspicion of misconduct in public office.

"The arrested man has now been released under investigation.

"We can also confirm that our searches in Norfolk have now concluded."

Mountbatten-Windsor was arrested at his Sandringham home on Thursday morning on suspicion of misconduct in a public office.

King Charles, his older brother, subsequently insisted that the "law must take its course".

The 77-year-old monarch said in a statement: "I have learned with the deepest concern the news about Andrew Mountbatten-Windsor and suspicion of misconduct in public office. 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."

Oliver Wright, the Assistant Chief Constable at Thames Valley Police, has also released a statement.

He said: "Following a thorough assessment, we have now opened an investigation into this allegation of misconduct in public office.

"It is important that we protect the integrity and objectivity of our investigation as we work with our partners to investigate this alleged offence.

"We understand the significant public interest in this case, and we will provide updates at the appropriate time."