The Bahamian island where Prime Minister Justin Trudeau took a vacation that is now the subject of an ethics investigation is owned by a company connected to a secretive web of corporations located in countries known to be offshore tax havens.

Bell Island, a private property nestled in the turquoise waters of the Exumas, has been widely known as the tropical retreat of the Aga Khan, a longtime Trudeau family friend.

Pictures and video of Bell Island obtained by CBC News show an idyllic location. An elegant, modern cream-coloured main house. A landscaped terrace surrounded by tropical flowers overlooking the water. Waterfront gazebos with thatched roofs and wooden pathways leading to ocean lookouts.

However, a CBC News investigation into Bell Island and the helicopter that carried Trudeau to the tropical retreat over the Christmas holidays has found a trail that includes several different companies and four countries known for their favourable tax rules and their ability to keep secrets.

Bell Island is located in the turquoise waters of the Exumas chain of islands in the Bahamas. (CBC)

The legal ownership of Bell Island involves several shell companies and nominee directors with links to Swiss banking giant Credit Suisse. The reasons for the complex corporate structure are unclear, and officials connected to the Aga Khan have refused to comment.

"Our policy is not to comment on any matters pertaining to His Highness's private affairs," said Semin Abdulla, communications manager for the Aga Khan Development Network.

Setting up offshore companies is legal and there can be legitimate reasons for using networks of offshore companies with nominee directors.

However, experts say it is also the kind of structure often used by those who are trying to hide assets or avoid or evade taxes. While tax avoidance can be legal, evading taxes is not.

The Aga Khan is scheduled to be in Ottawa Tuesday to open the new headquarters of the Global Centre for Pluralism, an education and research centre built in part with $30 million from the Canadian government.

Circle and Triangle

A title search of Bell Island conducted for CBC News reveals it is legally owned by Island of Discovery Ltd., a Bahamas-registered company set up only two months before the island was purchased from Exuma Bell Island Ltd. in March 2009 for $100 million US.

Island of Discovery Ltd. is in turn connected to at least two companies mentioned in the Panama Papers, a cache of 11.5 million documents leaked from the Panamanian law firm Mossack Fonseca and obtained by the International Consortium of Investigative Journalists (ICIJ).

One is Triangle Administration Ltd., a company originally registered in the British Virgin Islands that is listed as president and as a director of Island of Discovery Ltd.

Another company, Circle Corporate Services, also originally incorporated in the British Virgin Islands, is listed as secretary for Island of Discovery Limited.

Triangle Administration and Circle Corporate Services appear together in the ICIJ database in connection with many other companies. They were both incorporated on Dec. 6, 1999. On Jan. 7, 2013, both companies moved their registration from the British Virgin Islands to the Bahamas.

Chart of Island of Discovery's corporate structure showing its board of directors consists of Triangle Administration Services and Circle Corporate Services. (ICIJ)

Credit Suisse, a leading Swiss-based financial institution with a reputation for keeping its clients' secrets very secret, appears to play a key role in the corporate structure around Bell Island.

Credit Suisse Trust is listed as an intermediary for Island of Discovery.

The names of all of the directors of Triangle Administration correspond to names of employees of Credit Suisse at that time.

When the Panama Papers stories began to emerge, Credit Suisse's CEO Tidjane Thiam said the bank does use offshore financial structures for wealthy clients but does not condone tax avoidance.

The Panama Papers leak sent shock waves around the world, lifting the veil of secrecy that enabled many wealthy individuals and public officials to avoid or evade taxes in their home countries. Many of the documents outlined structures similar to those behind the ownership of Bell Island.

Denis Meunier, a former deputy director of the Financial Transactions and Reports Analysis Centre (FINTRAC) who viewed the documents located by CBC News, said there can be a variety of reasons to set up webs of related offshore companies.

A wooden pathway leads to a scenic lookout on Bell Island. The island was purchased in 2009 for $100 million US by Island of Discovery, a Bahamas-registered company created two months before the purchase. (CBC)

"What appears to me is what is quite similar to what we've seen in other situations in complex corporate structures is that there is an objective here — either to minimize tax or to distance the beneficial owner from the source of funds. It could be for totally legitimate reasons — that remains to be seen."

Kim Marsh, a retired RCMP officer who now works in the private sector with IPSA International, has years of experience tracking complicated financial arrangements. He said it is common for wealthy individuals to own property through companies. What is less common, he said, is setting up layers of companies.

"When you see layering, different layers, then that puts alarm bells up right away. Why do that? All you are doing is hindering someone who is trying to investigate and get to the bottom of a situation as to who is the beneficial owner."

Offshore tax havens have come under increasing scrutiny by Canada and other G7 governments in recent years, especially in the wake of the Panama Papers. Trudeau has said his government takes the issue of tax avoidance and evasion "very, very seriously."

Looking out from Bell Island in the Bahamas at night. (CBC)

Kate Purchase, director of communications for the PMO, said the complex web of companies around Bell Island was news to Trudeau.

"The prime minister was not aware of the corporate structure."

Purchase says it won't have any impact on the Canadian government's grants to the Aga Khan Foundation.

"The foundation is an internationally recognized not-for-profit organization that focuses on international development. Any money granted by the government of Canada is done so in keeping with the foundation's mandate."

Visit focus of ethics investigation

Trudeau has come under fire in the House of Commons for his trip to Bell Island and is facing an investigation by Conflict of Interest and Ethics Commissioner Mary Dawson for the vacation and for violating a rule that prohibits a prime minister or cabinet minister from accepting travel on a private aircraft unless it is first cleared with the ethics commissioner's office.

In an interview with CBC News, Dawson said the ownership of Bell Island is unlikely to affect her investigation.

"I don't think anything would change. As long as he (the Aga Khan) had the right to be on it," she said, indicating her investigation centres more on the question of the contact between the Aga Khan and Trudeau.

Prime Minister Justin Trudeau meets with the Aga Khan on Parliament Hill in Ottawa in 2016. The Aga Khan is an honorary Canadian citizen and addressed Parliament in 2014. (Sean Kilpatrick/Canadian Press)

Trudeau has defended the trip, arguing that the Aga Khan — a billionaire and spiritual leader to an estimated 20 million Ismaili Muslims — is a longtime family friend and that the helicopter was the only way to get to the island.

However, a government technician who stayed with Trudeau on the island arrived by commercially chartered seaplane.

The Aga Khan Foundation Canada, which lists the Aga Khan as its chairman in its most recent filings with the Canada Revenue Agency's charities section, has received millions of dollars in federal government grants over the years for its international development projects.

It is registered to lobby several government offices, including the Prime Minister's Office.

His Highness Prince Karim Aga Khan IV is often listed as one of the richest men in the world. While he is a philanthropist and spiritual leader, he has also earned a reputation over the years as a savvy investor and businessman.

In addition to Island of Discovery Ltd. and the companies that control it, documents obtained by CBC News under the Access to Information Act identify yet another company associated with Bell Island.

A handwritten notation on the travel expenses for Privy Council technician Brad Cotten's trip indicates a $1,200 US payment for Cotten's accommodation on the island was "to be remitted to Lexthree Ltd."

Lexthree Ltd. is also incorporated in the Bahamas. Its three directors — James Galbraith, Alan Abela and Jane Piacentini-Moore — have other ties to the Aga Khan. Abela and Piacentini-Moore are listed as directors of the Luxembourg-registered company Marine Promotion Services S.A., which also included the Aga Khan as a director in documents filed in 2011.

In a May 2016 photo with the Aga Khan, Piacentini-Moore was listed as the head of international financial affairs for the Ismaili Imamat, the Aga Khan's religious office.

Jane Piacentini-Moore, left, with the Aga Khan, Portuguese President Marcelo Rebelo de Sousa and top officials of the Ismaili Imamat in May 2016. (AKDN/Luis Filipe Catarina from AKDN.org website)

Helicopter registered in Utah

The helicopter that whisked Trudeau and his family from Nassau to Bell Island isn't owned in the Aga Khan's name either.

The helicopter's registered owner is an aircraft trust based at the Wells Fargo Bank in Utah.

There are a number of reasons that can prompt someone to use an aircraft trust. While they can be used for tax purposes, aircraft trusts can also be used to simply meet the requirement that the owner of an aircraft registered in the U.S. has to be an American or a company based in the U.S.

The AB139 helicopter, serial number 31012, started out life registered in Luxembourg with a company called One Thirty Nine Sarl listed as the owner and Aiglemont S.A. as the operator. In 2016, Abela and Piacentini-Moore were listed as directors along with Olivier Hamou, a financial services adviser who appears as an administrator of One Thirty Nine Sarl.

Photos of the helicopter taken in 2008 at the Ascot Racecourse Heliport show the Aga Khan's emblem on the tail.

The helicopter, still owned by One Thirty Nine, was re-registered in Bermuda in 2010 then re-registered later that same year in the U.S as N-139AK in the name of the Wells Fargo Bank aircraft trust.

Plane spotters contacted by CBC News say it is the only helicopter they regularly see around the airport in Nassau.

Dawson told a parliamentary committee on May 2 that she wants to finish her open investigations by the time her mandate expires on July 8.

Elizabeth Thompson can be reached at elizabeth.thompson@cbc.ca