A spokesman for Russian President Vladimir Putin says he is the "main target" of the media investigation into offshore accounts, but that he is not implicated in any wrongdoing.
The documents published by more than 100 media outlets alleged that Mr Putin's friends, including a leading cellist, were engaged in an offshore scheme.
Mr Putin's spokesman Dmitry Peskov says "it's obvious that the main target of such attacks is our president", and claimed that the publication was aimed at influencing Russia's stability and parliamentary elections scheduled for September.
Mr Peskov said international media had wrongly focused on Mr Putin instead of other world politicians, even though he was not implicated in any wrongdoing, and suggested the Washington-based International Consortium of Investigative Journalists, a key player in the publication, had ties to the US government.
Meanwhile, the French president said the leaked documents from a Panamanian law firm are "good news" because it will help the state to recover money from people who have committed tax evasion.
Francois Hollande, speaking to reporters during the visit of a tech company in the Paris suburb of Boulogne-Billancourt, said "the whistleblowers do a useful work for the international community; they're taking risks, so they must be protected".
Last year, the French tax administration recovered €12bn from people who had committed tax evasion or tax avoidance, according to the French president.
Regarding the French clients of the Panamanian firm Mossack Fonseca, "all the investigations will be made" and potential trials "will be held", Mr Hollande says.