Founding partner Ramon Fonseca said the firm, Mossack Fonseca, which specializes in setting up offshore companies, had broken no laws and that all of its operations were legal.
Nor had it ever destroyed any documents or ever helped anyone evade taxes or launder money, he added in an interview with Reuters.
Company emails, extracts of which were published in an investigation by the US-based International Consortium of Investigative Journalists (ICIJ) and other media organizations, were "taken out of context" and misinterpreted, he added.
The more than 11.5 million documents leaked from the law firm have caused public outrage over how the world's rich and powerful are able to stash away their wealth and avoid taxes while many people suffer austerity and hardship.
