HMRC has said it is ready to follow up allegations of money laundering and tax avoidance among the rich and powerful after a massive leak of confidential data.
British MPs are reported to be caught up in the scandal involving Panama law firm Mossack Fonseca.
The information was passed to German newspaper Suddeutsche Zeitung and has been shared through the International Consortium of Investigative Journalists (ICIJ).
HMRC director-general of enforcement and compliance Jennie Grainger said they had approached the ICIJ for access to the material.
She added: "We will closely examine this data and will act on it swiftly and appropriately.
"Our message is clear: there are no safe havens for tax evaders and no-one should be in any doubt that the days of hiding money offshore are gone.
"The dishonest minority, who can most afford it, must pay their legal share of tax, like the honest majority already does."
The financial watchdog ordered banks and businesses to check whether they have links to a law firm at the centre of the Panama Papers leak.
In a letter to the European Council President in 2013 Mr Cameron argued offshore trusts should not be subject to new transparency proposals.
The nature of the tax avoidance carried out by Blairmore Holdings may have been misunderstood.