Prince Charles's private estate appears to triple offshore investment in just over a year

The Queen's forays into offshore investing may have been the Paradise Papers' biggest surprise, but in terms of impactthey are easily eclipsed by a single, apparently very profitable deal made by Prince Charles.

Leaked documents show that in just one buy-and-sell transaction, the Prince of Wales'sprivate estate, the Duchy of Cornwall, appears in just over a year to have tripled an estimated $100,000 US investment in an offshore company co-run by one of his closest friends.

Leaked board minutes in the Paradise Papers show that from the purchase, in February 2007, the company, which specializes in carbon offsetting, also committed to treating his stake as a sensitive secret.

All the while, the heir to the British throne continued to publicly promote carbon offsetting a subject he's repeatedly spoken about even as he was invested in it.

None of the new revelations, which show the prince had millions more invested offshore, suggest illegal action. But they raise questions about the rules surrounding conflict of interest where royals are concerned, and, for the second time this week about whether senior royal figures are transparent enough about their sources of income especially if they're investing offshore.

• Read CBC's full coverage of the Paradise Papers leak

"The real problem with these revelations even if Charles had no knowledge whatsoever of what was going on, is that the optics are terrible," said David McClure, a royal finances expert, told CBC News. "It paints the future king of Britain in a bad light. It damages the brand of the British monarchy."

The peek into the prince's offshore dealings comes from a massive offshore leak obtained by the German newspaperSuddeutscheZeitungand provided to the International Consortium of Investigative Journalists, which organized a global collaboration that included the Guardian newspaper and the BBC in the United Kingdom as well asCBCNews in Canada.

Indirect stake

Through the Paradise Papers, it emerged for the first time on Sunday that the Queen had about 10 million pounds in investments offshore, including an indirect stake in a controversial chain of rent-to-own stores that just last month regulators ruled was not a responsible lender.

The Queen's private estate, the Duchy of Lancaster, said it did not know it held stakes in the chain until questions came from journalists.

Documents show Prince Charles's private estate purchased 50 shares in early 2007 in the Bermuda-based Sustainable Forestry Management Ltd., a now-defunct company that specialized in carbon offsetting. The price tag is estimated to have been in the $100,000 US ballpark.

• Queen's estate 'not aware' it held indirect offshore investment in stores accused of exploiting poor

Nearly a year and a half after the purchase, in June 2008, another document indicates the Duchy of Cornwall transferred its shares to another buyer. The purchase price is noted as $325,000, more than triple the initial investment.

The Prince of Wales has long spoken out in favour of sustainable forestry and carbon offsetting, and that did not change during the period when he held his stake in the company.

A speech prepared for Prince Charles for a July 2, 2007 event says: "We need to develop a new credit market which will give a true value to carbon and the ecosystem services that rainforests provide the rest of the world."

The BBC reported that the prince gave three major speeches which touch on the subject in the seven months after his private estate acquired the stakes.

Speaking out on climate change

A spokespersonfor Clarence House toldCBCNews in a statement: "He has certainly never chosen to speak out on a topic simply because of a company that [the Duchy] may have invested in."

"Carbon markets are just one example" of actions the prince has championed to "slow or halt the damage that is being done" by climate change, the spokespersonsaid.

In a Guardian newspaper investigation, minutes were spotted from a meeting of the board of directors of Sustainable Forestry Management Ltd. on Feb. 23, 2007, indicating the purchase was made possible with help from Hugh vanCutsem.

He and Prince Charles had been friends since they attended university in the1960s, and the vanCutsemfamily has been a fixture in Prince Charles's life ever since. The elder vanCutsemdied in 2013.

In the documents, the chairman is quoted as having "thanked Mr. vanCutsemfor his introduction of the Duchy of Cornwall and asked that the board unanimously agree that the subscription by the Duchy of Cornwall be kept confidential except in respect of any disclosure required by law."

Another document says vanCutsem"asked that a set of documents be prepared for the Prince of Wales office" about a scheme the company supported advocating the use of carbon credits.

In a statement, a Duchy of Cornwall spokespersontoldCBCNews the Prince of Wales "does not have any direct involvement in the investment decisions taken by the Duchy. These are the responsibility of the Duchy itself."

The spokespersonadded the investments "do not derive any tax advantage whatsoever."

The Duchy of Cornwall was set up 680 years ago to provide a private income to the heir to the throne.Its net assets are in the range of 896 million pounds.

Tax exempt but paying taxes

Prince Charles and his Duchy are tax exempt, but like the Queen, he has been voluntarily paying income tax since 1993.

The Duchy owns mostly commercial and residential real estate as well as land, some of which has been harnessed to help produce the Prince of Wales'sprofitable organic food enterprise.

The Duchy also has a financial investment portfolio. Its website says the prince is "actively involved in running the Duchy."

There have been calls in the past for more transparency in the Duchy's workings and more scrutiny of the details of generating an income for Prince Charles.

In 2016-17, the Duchy paid Prince Charles who is also the Duke of Cornwall, the longest serving in the title ever 20.7 million pounds in income, a raise of 1.2 per cent over the previous year.

The website says the income is there for him to spend as he sees fit, but that Prince Charles uses "a substantial proportion of his income" to fund the "public and charitable work as well as the public and private lives of his family" including his wife, Camilla, the Duchess of Cornwall; his son Prince William and his family; and his son Prince Harry.

Prince Charles is not entitled to access the Duchy's capital holdings, which will be passed on to William, the likely next Duke of Cornwall, when his father takes the throne.