UK monarchy reels from Andrew's stunning arrest
The disgraced royal was "released under investigation" late Thursday, with police believed to be continuing Friday searches of his former home on the royals' Windsor estate, west of London.
In a sensational development in investigations into his links to the late US sex offender Jeffrey Epstein, Andrew spent around 11 hours in custody after police arrested him on suspicion of misconduct.
Officers swooped early Thursday on his home in Sandringham, eastern England, taking him into custody at a nearby police station while also raiding his former Windsor home.
It prompted the king to swiftly issue a rare personally signed statement insisting "the law must take its course", as he reiterated Buckingham Palace would support the police probe.
"It's a hugely significant moment for the British monarchy," royal expert Ed Owens told AFP, noting much remained unclear including whether Andrew would be criminally charged.
"It's the unknown elements in this particular instance that I think pose so much concern and arguably a threat to the monarchy."
Almost all Britain's newspapers carried on their front pages Friday a photograph of the disgraced royal, leaving the police station in a vehicle looking haggard and wild-eyed.
"Downfall," screamed the Daily Mail headline.
The Sun tabloid noted that like anyone arrested, Andrew would have had a DNA saliva swab taken along with his finger prints and a photograph.
'So bad'
The day of drama in Britain sent shockwaves around the world, with US President Donald Trump calling it "very sad".
"It's so bad for the royal family," he told reporters.
Andrew's arrest follows new revelations last week that the ex-prince appeared to have sent Epstein potentially confidential documents while serving as a UK trade envoy, a post he held from 2001.
In a November 2010 email seen by AFP, Andrew appeared to share with the US financier reports on his visit to several Asian countries.
Epstein had been convicted in the United States in 2008 of procuring a child for prostitution.
Official guidance is thought to stipulate that trade envoys have a duty of confidentiality over sensitive commercial or political information related to their official visits.
The former prince's humiliating day in custody, which coincided with his 66th birthday, was the most dramatic yet in his years-long fall from grace.
'Difficult'
King Charles III last year stripped his brother of his titles and ordered him to leave his Windsor mansion -- though he does remain eighth in the line of succession.
That followed one of Epstein's accusers, Virginia Giuffre, last year recounting in shocking detail in her posthumous memoirs claims that she had been trafficked three times to have sex with Andrew, twice when she was 17.
Andrew has previously denied any wrongdoing in his associations with Epstein.
He settled a US civil lawsuit in 2022 brought by Giuffre while not admitting liability.
Charles sought to project an air of business-as-usual Thursday, carrying out several public duties, including opening London Fashion Week.
But royal commentators were in no doubt that the monarchy was facing its most severe crisis in decades.
Royal historian Anna Whitelock said it was the first arrest of a member of Britain's royal family in centuries - possibly stretching back to Charles I's surrender to the Scots army in 1646.
"Usually there is the usual 'keep calm and carry on' but it's going to be very difficult in these circumstances," she told AFP.
The police probe into misconduct in a public office allegations follow the US justice department last month releasing millions of files from its investigation into Epstein.
The offence carries a maximum sentence of life imprisonment, according to the Crown Prosecution Service.
At least nine UK police forces have confirmed they are assessing claims stemming from the Epstein files, many related to Andrew.