Georgian Prime Minister Bidzina Ivanishvii and Azerbaijani President Ilham Aliyev have been named as owners of companies registered in the offshore tax haven of the British Virgin Islands, according to a 15-month investigation by the Washington, DC-based International Consortium of Investigative Journalists.

The list of such owners, published in an April 3 report called "Secrecy for Sale: Inside the Global Offshore Money Maze," names Ivanishvili as the director of the Bosherton Overseas Corporation, registered in the British Virgin Islands in 2006 and "still in existence," according to the report. Aliyev and his wife, Mehriban, were listed as directors of Rosamund International as of 2003, the year Aliyev first came to power.

Their daughters, Arzu and Leyla, are registered as the director and a shareholder in Arbor Investments, and in LaBelleza Holdings Ltd and Harvard Management Ltd, respectively.

Ivanishvili, a self-made billionaire whose wealth helped propel his Georgian Dream coalition to power in Georgia's October 2012 parliamentary elections, has denied that he owns any shares in the Bosherton Overseas Corporation.

A spokesperson told Georgian media on April 5  that the prime minister had disposed of the shares before his campaign for public office began in 2011, though noted that "in the past" he had had "a business link" with the company." Georgian law forbids public officials to have a controlling stake in companies. "Bidzina Ivanishvili more than once has declared that to guarantee the maximum transparency, he will decisively meet all of the law's requirements and will make public information about his personal finances," the prime minister's press service announced, Negtazeti.ge reported.

President Aliyev has not issued any statement about the report.

The Aliyev family, though, has been implicated before in eyebrow-raising business transactions.

In 2010, The Washington Post reported that Aliyev's son, Heydar, then 12 years old, was the owner of "nine waterfront mansions" in Dubai. In 2012, as Baku was readying to host the Eurovision extravaganza, Radio Free Europe/Radio Liberty reported that the presidential family, including First Lady Mehriban Aliyeva, Eurovision's organizing chairperson, had ownership ties to the construction company building the festival's main venue, the Baku Crystal Hall.

Aside from the construction company, Aliyev's daughters also have been linked to stakes in a gold field, a private telecommunications company, and an airline service company, among other property.

A presidential spokesperson commented to Radio Free Europe/Radio Liberty's Azeri-language service, though, in reference to the first family's various alleged business activities that there is "nothing unusual" here. "Each one of us, like any citizen of Azerbaijan, has the right to do business," he said.

While offshore tax havens by themselves are not illegal, the report found, noted The Guardian, one of the project collaborators, that "the secrecy and lax oversight offered by the offshore world appears to allow fraud, tax-dodging and political corruption to thrive."