The searchable database built on just a portion of the documents leaked from the Panama law firm Mossack Fonseca reveals more than 360,000 names of individuals and companies behind the anonymous shell firms, the ICIJ said.
Reports already published in April based on the explosive dossier linked some of the world's most powerful leaders, including Russian President Vladimir Putin, British Prime Minister David Cameron and others to unreported offshore companies.
The data forced the resignations of Iceland's prime minister Sigmundur David Gunnlaugsson, and Spain's industry minister Jose Manuel Soria.
Until now access to the total cache of 11.5 million documents, originally provided by a mysterious "John Doe", was restricted to the ICIJ and a select group of international media.
ICIJ said Monday it is publishing some of the information catalogued in a database "in the public interest," as a global movement against tax evasion and the secrecy accorded the beneficial owners of anonymous shell companies gains force.
The database "allows users to explore the networks of companies and people that used -- and sometimes abused -- the secrecy of offshore locales with the help of Mossack Fonseca and other intermediaries," the ICIJ said.
But it said it was not making available raw records online, nor was it putting all the information from the records out, in part to prevent access to some personal data and bank account details of those mentioned.