Emails handed to Buckingham Palace six years ago appear to show that Andrew Mountbatten-Windsor shared confidential information while he was a government trade envoy, it has been reported.

The BBC said on Saturday that an archive of more than 30,000 emails was handed to the lord chamberlain, the most senior officer in the royal household, in 2020.

The broadcaster said it had seen court documents to suggest the cache contained information about the former prince’s financial dealings.

Mountbatten-Windsor was arrested on his 66th birthday in February on suspicion of misconduct in a public office amid allegations that he passed sensitive government information to the disgraced financier Jeffrey Epstein while employed as a government trade envoy.

He denies wrongdoing.

The palace said it was “not possible to provide any comment on these matters” due to the “ongoing police inquiry”.

Thames Valley police issued a fresh appeal for information last week. The force indicated it could also investigate any allegations of sexual misconduct and is understood to be examining a claim that the king’s brother behaved inappropriately at Royal Ascot.

The emails sent to the palace in 2020 were said to have come from the account of British businessman Jonathan Rowland, an associate of Mountbatten-Windsor, and were reportedly taken during a dispute with an unnamed colleague.

The full contents of the emails are unknown, the BBC said, but they are understood to contain correspondence dating up to June 2013.

The broadcaster reported that they had then been obtained by Kevin Stanford, the former majority owner of the fashion chain All Saints, who had been engaged in a separate dispute over investments in the failed Kaupthing Bank, linked to Rowland’s father, David.

Earlier this year, the Telegraph reported that Mountbatten-Windsor had requested confidential information from the Treasury in 2010 about the financial crisis in Iceland.

The newspaper obtained emails that showed he shared details of the briefing with Jonathan Rowland, passing on the information “before you make your move”.

David Rowland had taken over the Luxembourg arm of Kaupthing Bank the previous year. It later became Banque Havilland and faced sanctions from regulators in the UK and the EU.

The BBC said Jonathan Rowland had confirmed that the messages had been obtained from his account as part of legal proceedings. It added that it had seen a document from 2021 that appeared to show the archive had been sent to the lord chamberlain in May the previous year.

The emails were said to have been forwarded to the palace just months after Mountbatten-Windsor had stepped down as a working royal. Authorities in Monaco and Luxembourg were also informed, the BBC said.

His fall from grace had come after a disastrous interview on the BBC’s Newsnight, in which he failed to apologise for his friendship with Epstein.

The presenter Emily Maitlis had also asked Mountbatten-Windsor about allegations made by the late campaigner, Virginia Giuffre.

Giuffre, who died by suicide last year aged 41, claimed she had been trafficked by Epstein to be abused by Mountbatten-Windsor. Although Mountbatten-Windsor denied her allegations and claimed not to have met her, he paid her an out-of-court settlement in 2022, thought to be worth about £12m.

In May 2020, the role of lord chamberlain was occupied by Lord Peel. The BBC said it had contacted him, but the palace had responded on his behalf.