Tax authorities in Australia and New Zealand are probing local clients of a Panama-based law firm at the centre of a massive data leak. Other jurisdictions are likely to follow suit following the leak of details of hundreds of thousands of clients in more than 11.5 million documents from the files of law firm Mossack Fonseca, based in the tax haven of Panama.

The biggest data leak in history has lifted the lid on how world leaders and top officials hide their cash in offshore accounts, with a money trail worth up to $2bn (£1.4bn) leading to a number of Russian President Vladimir Putin's close allies. Mossack Fonseca director Ramon Fonseca said in a phone interview on 3 April that his firm had no responsibility for any potential illegalities associated with the accounts.

Fonseca told Reuters: "We are a company who after almost 40 years has never been formally accused of anything. We are dedicated to doing legal structures which we then sell to intermediaries like banks or lawyers or accountants and they manage it from there and we do not have any control over that. We are not responsible for how they manage those structures however they may want to do them.

"We have formed more than 240,000 companies throughout our history and the vast majority of these for legitimate purposes. Of course, there are some that end up being used for illegitimate activities but that is not our responsibility because we are not the ones who are managing them, we are not acting on them."

The Australian Tax Office (ATO) said it was investigating more than 800 wealthy clients of Mossack Fonseca.