Over 2, 600 GB of data comprising more than 11 million documents about some 214, 000 hidden offshore companies owned by prominent people, including some from India, together make up for one of the biggest revelations called "Panama Papers".
The disclosures over the weekend by the International Consortium of Investigative Journalists (ICIJ) reveal how the rich and powerful use tax havens to hide their wealth.
The documents were leaked from one of the world's lesser known law firm Mossack Fonseca based in Panama.
ICIJ's probe is unprecedented and is said to be larger than the US diplomatic cables released by Wikileaks in 2010 and the secret intelligence documents given to media houses by Edward Snowden in 2013.
The ICIJ, together with the German newspaper Suddeutsche Zeitung and more than 100 other media partners, including the Indian Express from India, spent a year sifting through 11. 5 million leaked files to expose the offshore holdings of world political leaders, links to global scandals, and details of the hidden financial dealings of "fraudsters, drug traffickers, billionaires, celebrities, sports stars and more", the consortium said on its website.
The document trove includes nearly 40 years of data from the Panama law firm that has offices in more than 35 locations around the globe, and is one of the world's top creators of shell companies, corporate structures that can be used to hide ownership of assets, according to the consortium.
ICIJ's analysis of the leaked records revealed information on more than 214, 000 offshore companies connected to people in more than 200 countries and territories. The top leaders under the scanner include Russian President Vladimir Putin and Pakistan Prime Minister Nawaz Sharif among others.
The data includes e - mails, financial spreadsheets, passports and corporate records revealing the secret owners of bank accounts and companies in 21 offshore jurisdictions, including Nevada, Hong Kong and the British Virgin Islands.
ICIJ's data and research unit indexed, organised and analysed the 2. 6 terabytes of data that make up the leak, using collaborative platforms to communicate and share documents with journalists working in 25 languages in nearly 80 countries. All this was kept under wraps for about eight months since the investigation started.
The documents show how Mossack Fonseca helped clients launder money, dodge sanctions and evade tax. The Panama company has, however, denied any wrongdoing. It says it has operated beyond reproach for 40 years and has never been charged criminally.
Gerard Ryle, director of the ICIJ, said the documents covered the day - to - day business at Mossack Fonseca over the past 40 years.
"I think the leak will prove to be probably the biggest blow the offshore world has ever taken because of the extent of the documents, " he said.