The law firm at the centre of the "Panama Papers" global tax evasion scandal that brought down two world leaders has announced its decision to shut down operations, citing negative press and what it called unwarranted action by authorities.

"Reputational deterioration, the media campaign, the financial consequences and irregular actions by some Panamanian authorities have caused irreparable damage, resulting in the total ceasing of public operations at the end of this month," Mossack Fonseca said in a statement.

But it added a smaller group would continue working to address requests from authorities and other public and private groups.

Last August, co-founder Jurgen Mossack acknowledged the firm had closed most of its offices abroad after its damaged credibility caused business to flounder.

The "Panama Papers" scandal broke in 2016 when a leak of 11.5 million files from Mossack Fonseca's digital archive revealed how wealthy and influential figures across the world had created offshore businesses to safeguard assets.

The information was obtained by German newspaper Sueddeutsche Zeitung, which shared it with the International Consortium of Investigative Journalists.

It was released as a searchable database, with revelations continuing to be unearthed to this day.

Icelandic prime minister Sigmundur David Gunnlaugsson was forced to resign after it was revealed his family had offshore accounts, while former Pakistani prime minister Nawaz Sharif was disqualified for life from office after being implicated in the documents.

Other figures implicated included former British prime minister David Cameron, footballer Lionel Messi, Argentina's President Mauricio Macri, and Spanish filmmaker Pedro Almodovar.

At least 150 investigations were opened in 79 countries to examine possible tax evasion and money laundering, according to the US-based Center for Public Integrity.