Andrew Mountbatten-Windsor has been served with a summons requiring him to give evidence in a High Court fraud trial around 15 December, bringing disputed payments linked to his finances into public questioning. He is not accused of wrongdoing.

The summons was sought by Selman Turk, a former financial adviser defending allegations that he misled Nebahat Isbilen, an elderly, wealthy Turkish woman, and used her money for his own benefit. Turk strongly denies dishonesty.

Mountbatten-Windsor’s appearance would be his first public questioning since his BBC Newsnight interview in 2019, and an opportunity to hear his first public comments since being stripped of his titles. He is believed to be the first royal since the 19th century to receive such a witness summons.

Court documents set out competing explanations for a £750,000 payment to him. Isbilen alleges Turk misled her into making the transfer in the belief that it would secure help with a passport. Turk denies this, saying she offered the money on her own initiative as a gift to establish goodwill with the then duke, unrelated to any passport.

The transfer took place the day after Mountbatten-Windsor recorded his Newsnight interview, which was broadcast the following evening. He stepped down from royal duties soon afterwards. Isbilen’s lawyers contacted him in 2021, and the money was repaid. That repayment leaves the dispute over Turk’s conduct for the court to determine.

Another payment from Isbilen’s account, of around £768,000 in January 2020, will also come under scrutiny. Turk says it was a loan to Mountbatten-Windsor towards buying a Swiss chalet. Isbilen disputes that explanation, which has been challenged in earlier hearings.

Turk met Mountbatten-Windsor in autumn 2019 through Pitch@Palace, the former duke’s Dragons’ Den-style business pitching project. Social gatherings followed involving Turk and his family, Isbilen and the then Duke and Duchess of York.

Mr Justice Adam Johnson gave permission last month for Mountbatten-Windsor to be called. Given the seriousness of the allegations, the judge said Turk should have access to “the evidence he considers relevant and material”. Janes Solicitors, representing Turk, said he denies dishonesty and expects to be vindicated in court.

The summons was issued this week. The trial is expected to begin in mid-November, with Mountbatten-Windsor’s evidence scheduled for around 15 December. Witnesses usually attend in person, though he could appear by video.

After years of questions about the transparency of his finances, his testimony offers a rare opportunity to hear his explanations. Its legal purpose, however, is to help resolve the disputed handling of Isbilen’s money.