Prime Minister David Cameron's stockbroker father died leaving assets offshore in the tax haven of Jersey, a Channel 4 News investigation can reveal.
By Guy Basnett and Paul McNamara
Ian Cameron's offshore wealth is revealed in a legal document filed with courts on the island, where he had helped run a multi-million pound investment fund.
It has previously been widely reported that David Cameron's father (pictured above right, with his son) helped manage funds in tax havens in Panama and Jersey.
However, this is the first time he has been shown to have personally held wealth offshore.
Lawyers say the "grant of probate", attached to a copy of his English will, would only be filed if there were assets left in Jersey and the estate was worth more than £10,000.
But under Jersey law, the full value of the estate does not have to be publicly disclosed.
Mark Renouf, partner in leading Jersey law firm Hanson Renouf, said: "The only reason to have that document is because there are some assets situated in Jersey.
"We can't tell from the documentation, which is very normal, how much those assets were worth, except to say that there is no point in doing this if they were valued at less than £10,000, because you don't need to have a grant of probate under that value."
The revelation that his father held wealth in a tax haven could be uncomfortable for the prime minister, who has previously called for a crackdown on tax avoidance, branding some schemes "morally wrong".
The prime minister brought leaders of British tax havens to Downing Street in 2013 for a meeting about tackling tax avoidance and increasing transparency.
He said at the time: "Let's be clear about why this tax issue matters. I mean, if companies don't properly pay their taxes, and individuals don't properly pay their taxes, we all suffer as a result. So it's important we do get our own house in order."
The grant of probate (pictured above) was filed with the Royal Court of Jersey in March 2011, six months after Mr Cameron senior died, aged 77, while on holiday in the south of France.
It names his wife Mary, son Alex, and daughter Tania as executors.
Legal experts said the structure of the will meant any Jersey assets would go to his wife Mary, as part of a process of distributing unspecified wealth, known as "residue".
However, the will states if she had died before her husband, then this residual wealth would have been shared out between the prime minister and his sisters, Clare and Tania.
There is no suggestion that David Cameron has benefited from any of the offshore assets, or that he even knew his father had held assets in a tax haven. There is also no suggestion of any illegality or wrongdoing by Ian Cameron or his family.
The Jersey Grant of Probate, obtained by investigative news agency OpenWorld News, concerns Mr Cameron senior's "moveable estate", such as cash and investments.
Channel 4 News has also obtained documents showing he owned shares in a Jersey fund he helped to manage, known for a time as Close International Equity Growth Fund.
Filings shortly before he resigned in 2009 showed he held at least 6,000 shares. These shares are understood to be included in Mr Cameron senior's Jersey estate after he died.
The fund, which was open to a range of investors to join and changed its name repeatedly, grew to be worth around £23m for its investors by the date the Jersey grant was obtained, in 2011.
The former stockbroker also set up Blairmore Holdings Inc in Panama in 1982, named after the Cameron's former family home in Scotland.
A prospectus for the fund in 2006 said: "The directors intend that the affairs of the Fund should be managed and conducted so that it does not become resident in the United Kingdom for United Kingdom taxation purposes."
There is no evidence that Mr Cameron senior had personal wealth in the Panama fund.
Questions about transparency
The existence of assets held in Jersey raises questions about Mr Cameron senior's wealth.
In 2009 compilers of the Sunday Times Rich List estimated his wealth to be around £10m - a calculation that cannot be verified by Channel 4 News.
However, after his death, the net value of his estate in England was put at £2.7m.
The grant was drawn up by law firm Ogier, which specialises in five offshore tax havens, including Jersey, the Cayman Islands and the British Virgin Islands.
Channel 4 News asked the prime minister what the value of his father's Jersey estate was, and whether any of that money remains offshore.
The Jersey grant raises questions about whether he is serious about tax transparency.
In 2012 the government promised to publish the tax returns of senior Cabinet members. In 2014 the prime minister said he remained committed to releasing his tax information.
And as recently as January this year, the prime minister said he was "very relaxed" about publishing his tax affairs. However, to date, nothing has been published.
A spokesman for David Cameron said: "David Cameron did not discuss the writing of his father's Will with him, or know the contents of it, before he died.
"He was not an executor of the Will. He was a beneficiary of a cash legacy.
"He does not have any offshore assets, accounts or private shareholdings of any description.
"In government, Conservatives have done more than any other party to crack down on tax avoidance and evasion, delivering £7bn of annual savings over this parliament with the tax gap now lower than any year under Labour. We will continue to ensure that everyone pays their fair share."
Number 10 declined to give the value of the Jersey estate, or say what assets were held offshore.