A senior aide to Prince Andrew privately admitted to an alleged Chinese spy that the duke’s BBC Newsnight interview had been “ill advised”, court documents show.

Files disclosed to the BBC and other media outlets reveal how the prince’s aide Dominic Hampshire thanked Yang Tengbo for standing by the embattled duke in the months after he had sought to explain on TV his friendship with sex offender Jeffrey Epstein.

He told the Chinese businessman that the Newsnight appearance had been “unsuccessful”.

Last month a court rejected Mr Yang’s appeal against being banned from the UK, after an intelligence assessment that he could be secretly working for the Chinese state. Mr Yang has denied all wrongdoing.

The Special Immigration Appeals Commission (Siac) previously said that Mr Yang had won an “unusual degree of trust” from the royal.

Mr Yang came to study in UK in 2002 and later set up a series of China-related travel and business consultancy firms.

He took on a role in the China-based version of Prince Andrew’s “Pitch@Palace” events, in which entrepreneurs sell their ideas to investors.

Documents from the Siac case now show that friendship deepened in the wake of the November 2019 Newsnight interview, in which the Duke was questioned over his relationship with Epstein, and denied assaulting Virginia Giuffre.

Writing in March 2020, Prince Andrew’s senior aide Dominic Hampshire told Mr Yang how much his “principal” appreciated the fact that he had stood by him.

“We have dealt with the aftermath of a hugely ill-advised and unsuccessful television interview,” wrote Mr Hampshire on official Buckingham Palace notepaper.

“We have wisely navigated our way around former Private Secretaries and we have found a way to carefully remove those people who we don’t completely trust.

“Moreover, in what originally seemed like a lost cause, you have somehow managed to not only salvage but maintain and then incredibly, enhance the reputation of my principal in China.

“Under your guidance, we found a way to get the relevant people unnoticed in and out of the house of Windsor.

“We orchestrated a very powerful verbal message of support to China at a Chinese New Year’s dinner and between the three of us, we have written, amended and then always agreed a number of letters at the highest level possible.”

The disclosure on Friday comes after separate court documents revealed Prince Andrew appeared to have been in touch with Epstein for longer than he had previously admitted.

An email from a “member of the British Royal Family”, believed to be Prince Andrew, was sent to Epstein in February 2011, court documents showed.

In the Newsnight interview, the prince said he had not seen or spoken to Epstein since December 2010, when he visited the financier’s home in New York.