This is what we know about the issue.
Prince Andrew is now a non-working member of the royal family
AFP via Getty Images
What is Prince Andrew accused of?
The royal duke has had close ties with a businessman, who was given the code name H6.
It was said that the two met through “official channels” and that nothing sensitive was ever discussed.
Yang Tengbo came to prominence in March 2023 when Suella Braverman said he should be excluded from the UK as part of a government-identified problem of Chinese infiltration in Britain.
H6 then brought a case to the Special Immigration Appeals Commission in July 2023, where judges were told that he had been in a position to generate relationships between prominent UK figures and senior Chinese officials “that could be leveraged for political interference purposes”.
They also said that H6 had downplayed his relationship with the Chinese state which, combined with his relationship with Andrew, represented a threat to national security.
Who is H6? What do we know about Yang Tengbo?
The Chinese national had been due to be named after an anonymity order made in May 2023 was lifted by judges at the specialist tribunal.
However, the day before the judgment was due to be published, he made a successful bid at the high court for a temporary block on being named, which has now been lifted.
And so, on Monday a high court judge named H6 as Yang Tengbo, a 50-year-old businessman who is sometimes known as Chris Yang.
His identification came after his lawyers said he was not looking to protect his identity.
He is said to have become a “close” confidant of the Duke of York and has also been pictured with senior politicians including David Cameron and Theresa May.
Both former prime ministers who are now members of the House of Lords have said that photos of them together are among the hundreds that were taken while in office and have no memory of meeting him.
Mr Yang has argued that the widespread description of him as a spy is “untrue”.
He said: “I have done nothing wrong or unlawful and the concerns raised by the Home Office against me are ill-founded. The widespread description of me as a ‘spy’ is entirely untrue.”
“When relations are good, and Chinese investment is sought, I am welcome in the UK,” he said, adding that the heat around him had come due to the “political climate”.
“When relations sour, an anti-China stance is taken, and I am excluded.”
A spokesperson for China’s ministry of foreign affairs said: “China has always acted in an upright and honest manner and has never engaged in any deception or interference, so it is not worthwhile to refute this kind of groundless speculation which is based on one’s own judgement.”