Police are studying a 147-page Mail on Sunday dossier detailing how Andrew Mountbatten-Windsor was allegedly sharing confidential government information with wealthy business contacts while working as a trade envoy.

The MoS first alerted Buckingham Palace to the bombshell material in 2019 – long before detectives opened their investigation into the former prince on suspicion of misconduct in public office – only to be brushed aside with an official assurance that the then-duke was working to promote Britain.

Three months ago, we further disclosed how that same year a whistleblower had warned the King, when still Prince of Wales, about Andrew's business activities.

Following those revelations, Thames Valley Police, the force investigating Andrew, formally requested our material last month.

Yesterday, the BBC followed up the MoS's investigations by leading its news bulletins with reports that the Lord Chamberlain, the most senior officer in the Royal Household, had received a cache of leaked emails in 2020.

The MoS dossier in the hands of the police contains incendiary emails making allegations that Mountbatten-Windsor plugged the business interests of property tycoon David Rowland and his son Jonathan while on taxpayer-funded trade missions meant to promote UK business.

The messages also seem to indicate Andrew requested a confidential briefing from Treasury officials in 2010 about problems in Iceland's banking industry, which he shared with the Rowlands.

David Rowland, a former tax exile, had taken over the Luxembourg arm of a failed Icelandic bank, Kaupthing, which became Banque Havilland, a private bank for the super-rich.

Our story in February revealed that a whistleblower who had detailed knowledge of Andrew's business dealings with David Rowland had sent an email to Charles, then Prince of Wales, via royal lawyers Farrer & Co, warning of 'David Rowland's abuse of the Royal Family'.

It said: 'The Duke of York's actions suggest that His Royal Highness considers his relationship with David Rowland more important than that of his family.'

The whistleblower then sent a second email to Mr Rowland, copying in Clive Alderton, Charles's private secretary, and Mark Bridges, the late Queen's solicitor at Farrer & Co. That message said: 'The evidence provided unequivocally proves that you have abused the Royal Family's name.'

The email further alleged that Mr Rowland had paid Andrew to procure a Luxembourg banking licence for Banque Havilland, and included what were claimed to be Andrew's bank account details.

It formed part of a raft of MoS revelations about Andrew's business activities, including that he had told Jonathan Rowland he had 'a very supportive chat' with prime minister David Cameron and Labour leader Ed Miliband, apparently at Prince William's wedding in April 2011, when questions were being raised over his trade envoy position following this newspaper's publication of the now infamous photograph of him clutching 17-year-old Virginia Giuffre.

Other emails suggested that Andrew secretly used an official trade mission to help strike a multi-million-pound deal for his business associates to sell oil to China, with the hope of making 'tons of money' with paedophile financier Jeffrey Epstein, and that a British ambassador had warned the government more than two decades ago that Andrew's behaviour as trade envoy was damaging his country and the Royal Family.

The Epstein files show Mr Mountbatten-Windsor promoting the Rowlands' business ventures and giving personal assurances for David Rowland as his 'trusted money man'. His former wife Sarah Ferguson was also recorded as receiving a 'Rowland bank loan'.

When the MoS approached the Palace in 2019 with the results of our investigation, it would only confirm the duke's role and insist 'the aim, and that of his office, was to promote Britain and British interests overseas, not the interests of individuals'.

When we asked them for comment this year about Charles being tipped off in 2019, a source cited the ongoing police investigation as a reason not to comment.

Asked by the BBC yesterday about the emails seen by the Lord Chamberlain, the Palace used the same excuse, saying: 'Since there is an ongoing police enquiry concerning Mr Mountbatten-Windsor, it is not possible to provide any comment on these matters.'

Former minister Norman Baker said the response was not good enough. He told this newspaper: 'The Palace needs to realise that their approach of 'never explain' is well past its sell-by date. They need to come clean about what they knew and when.'

And he pointed out that the BBC 'are at least seven years behind The Mail on Sunday'.

Rachael Maskell, Labour MP for York Central, yesterday called for a public inquiry into Andrew's role as trade envoy, saying: 'There are so many threads now... They are sitting on these emails and sitting on really sensitive information.

Speaking to Radio 4's Today programme, she said: 'We have to investigate the issue of unaccountable power and also the abuse of power in high office. The system built around the Royal Household has to be reviewed and an independent inquiry would be able to not only do that, but also hold power to account.'

Ailsa Anderson, press secretary to the late Queen from 2001 to 2013, told the same programme: 'The police investigation has to take its course and the Royal Household acted very, very promptly by saying that they would cooperate absolutely fully with the police investigation'.

She added: 'It would be wrong of me to speculate about what [the Palace] did or did not do. We operated differently 10, 15, 20 years ago... we did not know in 2010 what we know today.'

Mr Mountbatten-Windsor has denied any wrongdoing in his associations with Epstein and claims that he made any personal gain from his role as trade envoy.