Prince Andrew (right) with David Rowland at the financier's luxury home on the island of Guernsey who is said to have provided him with private jets

Prince Andrew made a secret deal to fly around the world on a £40million luxury jet owned by a controversial financier whose private bank he quietly promoted while working as Britain’s overseas trade envoy.

A leaked email reveals how Andrew fixed it so that property tycoon David Rowland’s sumptuous 14-seat plane was used for some of his overseas Royal engagements after the Prince became ‘frustrated’ with the ageing aircraft provided by the RAF.

Records unearthed by The Mail on Sunday show how in the last two years Andrew has travelled on the Global Express at least five times while on official Royal duties, some of which he combined with promoting his treasured Pitch@Palace project or Mr Rowland’s latest business venture.

The email also reveals how Andrew, Britain’s roving trade ambassador between 2001 and 2011, sought assurances that the aircraft would have tight security while it was on the ground at Farnborough airport in Hampshire, because ‘it was going to be used by members of the Royal Family’.

Last night, Buckingham Palace said the flights were not taxpayer funded but refused to explain how they were paid for, other than to say the matter was ‘private’. A spokesman also refused to say which Royals had used the jet or who met the security bill.

Sumptuous: The luxury interior of a Bombardier Global Express jet owned by Rowland, costing up to £7,600 per hour to hire, which was used by Prince Andrew to fly to the United Arab Emirates. In a leaked letter to a Bombardier sales executive, Rowland said: ‘The quality of it, from its flying capacity to its fantastic interior and paintwork, has exceeded all expectation’

The extraordinary deal was struck in 2010 when Prince Andrew was still UK trade envoy but records reveal he flew on the executive jet as recently as this May.

In October last year, records show the plane flew to the United Arab Emirates. The Court Circular reveals that only the next day Andrew was yet again cutting the ribbon on one of Mr Rowland’s banks following a multi-million-pound deal.

The Duke had previously opened a bank owned by the Rowlands in the tax haven of Luxembourg in September 2009 and then one in Monaco in 2012. In the eight days after opening the headquarters of the Anglo-Gulf Trade Bank in Abu Dhabi, Andrew attended three Pitch@Palace events there.

The Duke wrote to Mansour Ojjeh, President of Tag Group, where he outlined a deal claiming to have helped Rowland purchase his new Bombardier jet (pictured). He asked Ojjeh for reassurances that the jet would maintain high safety standards as it was to be used by the Royal family

Andrew’s use of the top-of-the-range jet is bound to raise questions over whether the Duke was left indebted to the Rowland family. In fact, in a separate gushing email to Jonathan Rowland – David’s 44-year-old son and loyal business lieutenant – Andrew barely disguises his joy at the arrangement.

‘I am deeply, deeply grateful to your father for making this possible,’ he wrote. ‘I have a completely different outlook on life and its possibilities now. Whilst trying not to let it go to my head! Very difficult!’

Last week, the MoS revealed how Andrew quietly plugged the Rowlands’ Luxembourg-based bank for the super-rich while on overseas trade envoy missions. We showed how the Duke allowed the Rowlands to shoehorn meetings into his trade tours so they could expand the bank and woo wealthy clients.

One senior Tory last night said the jet deal had ‘conflict of interest written in 6ft-high print’. Nigel Mills, before the Election a member of the Commons public accounts committee, pledged that if re-elected this week, he will demand a probe by the National Audit Office spending watchdog.

Prince Andrew attends a military air display event on November 25, 2010 in Abu Dhabi. In October last year, records show the Global Express plane flew to the United Arab Emirates. The Court Circular reveals that only the next day Andrew was yet again cutting the ribbon on one of Mr Rowland’s banks following a multi-million-pound deal

‘It poses real questions about whether when he was performing Royal duties he was doing that in the national interest or in the interests of his mates. And that is something which should be independently looked at,’ Mr Mills said.

With a range of more than 7,000 miles and a luxurious cabin fitted out to the exact requirements of the owner, the Global Express was certainly an impressive choice of jet. Gary Dukes, an account executive at Privé Jets, a US firm that brokers private jet travel, said such an aircraft would cost up to £7,600 per hour to hire, adding: ‘There is not a set price but hourly costs can be between £5,900 and £7,600 – that includes pilots, fuel, everything.’

David Rowland was thrilled by his new plane after a ‘delivery ceremony and dinner’ hosted by its manufacturer Bombardier in December 2010. ‘It is a great aeroplane!’ he wrote in a leaked letter to a Bombardier sales executive. ‘The quality of it, from its flying capacity to its fantastic interior and paintwork, has exceeded all expectation.’

It was a stark contrast to the tired RAF executive jets of 32 Squadron used by the Royals and other dignitaries. Some of the jets dated back to the 1970s and were unable to fly across the Atlantic.

The Duke combined a four-day visit to Abu Dhabi (pictured in 2009) and the Crown Prince and an international school with three Pitch@Palace events. Here he is presented a white Gyr falcon on behalf of Abu Dhabi

In the astonishing leaked email, Andrew told Mansour Ojjeh, President of Tag Group, the then owner of Farnborough airport, that he was fed up with the Government’s failure to replace the aircraft.

‘Over the last few years, I have been increasingly frustrated at the Government’s lack of action and inability to see the need for replacement of the aircraft of the current Royal Flight,’ he said. In the late 1990s, Andrew, then still a Royal Navy officer, recommended privatising the Royal Family’s helicopters. This led to the Queen leasing a US-built helicopter instead of using two RAF Wessex helicopters.

But in his email he lamented that he had failed to persuade the Government to also privatise the Royal Flight’s fixed-wing aircraft.

And in a series of extraordinary comments, he revealed to Mr Ojjeh that he had taken matters into his own hands and approached ‘a number of private providers’.

Buckingham Palace last week refused to say how many aircraft owners the Duke spoke to – but his friend David Rowland was clearly one of them. Andrew outlined to Mr Ojjeh a deal in which he claimed to have helped Mr Rowland purchase his new Bombardier jet by buying time on the jet ‘in advance’.

Pictured: Financier David Rowland arrives at Princess Eugenie's wedding to Jack Brooksbank. Ex-MP Nigel Mills is to demand a probe by National Audit Office spending watchdog into the £40m jet owned by the financier (pictured)

‘I successfully moved the helicopter provision from the RAF to Civilian commercial nearly 10 years ago but the fixed-wing element has been as I say, frustrating in the extreme. In order to do something I went to discuss with a number of private providers the possibility of finding an alternative solution.

‘This I have managed to do and in the process have helped the owner by buying a number of hours per year in advance to help him with a potential purchase.

‘Cutting a long story short, I have contracted with David Rowland for use of his aircraft (which I helped him purchase from Bombardier).’

Pictured: Conversations between Jonathan Rowland, Prince Sultan bin Salman and the King of Bahrain's advisor

Buckingham Palace also refused to explain the financing of the arrangement but the Duke’s claim to have paid for access to the jet raises more questions about his mysterious finances.

Andrew’s only official income amounts to a £20,000-a-year Navy pension and a reported £249,000 paid privately each year by the Queen to run his official office. The Prince’s reason for writing to Mr Ojjeh was to seek assurances that the jet would be kept securely at Farnborough, Britain’s private jet hub.

‘I am concerned about the security of this aircraft as it is going to be used by members of the Royal Family and I would like to know it is well secure whilst it is on the ground at Farnborough.’ The Prince sent a draft of the email to Jonathan Rowland, asking for ‘any comments/additions/deletions?’

The jet deal further illustrates the extraordinarily close ties between Andrew and David Rowland, who was a tax exile for more than 30 years and who helped pay off Sarah Ferguson’s debts. In 2010, David Rowland quit as Tory Party treasurer amid controversy surrounding his business affairs.

Andrew (pictured earlier this year) was expected to travel to the Middle East in mid November as part of his Pitch project but has cancelled plans following reported pressure from his family

The MoS can reveal how Prince Andrew appeared to use Mr Rowland’s jet to fly to the Middle East for a visit in which he gave the Royal seal of approval to another one of his friend’s lucrative business ventures. Buckingham Palace’s Court Circular shows that Andrew opened the headquarters of the Anglo Gulf Trade Bank in Abu Dhabi’s glittering Al Maqm Tower, a 37-storey glass skyscraper on October 16, 2018. The bank is a joint venture between AGTB Holdings, a Rowland family-controlled company, and Abu Dhabi’s Mubadala Investment Company.

Andrew was pictured cutting a ribbon in front of Edmund Rowland, David’s 34-year-old son who became the bank’s chief executive.

Rowland, Prince Andrew and Queen Elizabeth II before the start of the Gold Cup race on June 22, 2006. The Duke's most recent flight on Mr Rowland’s jet was in May, when he flew to Canada for a six-day visit. Publicly available flight records show the aircraft flew from Farnborough to Halifax Stanfield airport in Nova Scotia on May 23

Intriguingly, the Court Circular makes no mention of how and when Andrew arrived in Abu Dhabi. But the MoS has obtained flight records for Mr Rowland’s Global Express that show it flew from Farnborough to Abu Dhabi – a six-hour, 47-minute flight – the day before the opening ceremony. The bank’s bosses were thrilled the Duke had brought some Royal stardust to their launch.

‘Anglo-Gulf Trade Bank will have a real impact on the way that international trade is carried out and that is why the inauguration of our Abu Dhabi headquarters… by the Duke of York is such an important moment,’ said Jeremy Parrish, the bank’s chairman.

While in Abu Dhabi, the Prince also attended three events for Pitch@Palace – his business venture which matches investors with tech start-up companies – including one at Emirates Palace, a luxury five-star holiday resort.

Prince Andrew with King Hamad bin Isa Al Khalifa of Bahrain at the Royal Windsor Horse Show in May 2017

Prince Andrew’s most recent flight on Mr Rowland’s jet was in May, when he flew to Canada for a six-day visit. Publicly available flight records show the aircraft flew from Farnborough to Halifax Stanfield airport in Nova Scotia on May 23.

That night, according to the Court Circular, Buckingham Palace’s register of official engagements, the Duke attended a dinner hosted by Nova Scotia’s lieutenant governor.

The jet then appears to have whisked him to Toronto for more official engagements, including a visit to Lakefield College School – a private school in Ontario where, as a 17-year-old, he enjoyed a blissful six months. The visit could be his last. Following his disastrous BBC interview about links to Jeffrey Epstein, Lakefield’s head last month confirmed Andrew is no longer the honorary chairman of its foundation.

The 2nd International Festival of Falconry sponsored by the Emirates Falconers' Club from Abu Dhabi held in the grounds of the Englefield Estate,Theale, Berkshire, Britain. Buckingham Palace has said none of the Duke's flights detailed were paid for by the Sovereign Grant

The Canada tour was one of more than 30 foreign trips since 2014 in which Andrew promoted Pitch@Palace – he attended a so-called ‘boot camp’ for the project in Toronto and an event at the Art Gallery of Ontario. The Duke, known as ‘Air Miles Andy’, left Toronto on May 28, arriving in Farnborough the following day, according to the Court Circular. This exactly matched a six-hour, 13-minute flight recorded for Mr Rowland’s jet.

Pictured: Email exchanges between Andrew, his aide Amanda Thirsk and Jonathan Rowland

His schedule had also exactly matched the flight logs of Mr Rowland’s aircraft two months earlier. Andrew arrived at Bahrain International airport on the evening of March 25, according to the Court Circular. Mr Rowland’s Global Express touched down at the same airport at 7.22pm that night.

The Duke visited the Royal Navy’s £40 million support base at Mina Salman and had dinner with the King of Bahrain – and he also attended two Pitch@Palace events.

It was a similar picture in October 2017, when during a four-day visit to Abu Dhabi he combined visits to Abu Dhabi’s Crown Prince and an international school with three Pitch@Palace events.

This time, it appears he flew home on his friend’s luxury jet. The Court Circular records that he arrived at Luton airport on October 5 – as did Mr Rowland’s Global Express.

Buckingham Palace said: ‘The Sovereign Grant funds official overseas travel by members of the Royal Family, at request of Government. None of the flights detailed were paid for by the Sovereign Grant.’

The Rowlands declined to comment for legal reasons. Farnborough airport said: ‘We do not comment on flights operating from the airport.’