What are Panama papers, who leaked them and who have access to it?
People demonstrate against Iceland's Prime Minister Sigmundur Gunnlaugsson in Reykjavik, Iceland on April 4, 2016 after a leak of documents by so-called Panama Papers stoked anger over his wife owning a tax haven-based company with large claims on the country's collapsed banks. Reuters

After the biggest data leak ever in history exposed the financial wrongdoing of the world's rich and powerful, the focus has been on who leaked the data dump and how, as well as on who are the world's rich and powerful who figure in the Panama papers.

Initial reports, which have probably only skimmed through the top of the iceberg, shows law firm Mossack Fonseca, which has been largely under the radar for decades, helped the powerful and the rich launder money, dodge sanctions and evade tax.

The Past and present world leaders figure in the 11.5 million documents that offer a detailed look into the daily operations of Mossack Fonseca over the last 40 years.

As many as 12 current or former heads of state figure in the data, while around 60 people linked to current or former world leaders are also named.

These include Icelandic Prime Minister Sigmundur David Gunnlaugson, the family of UK Prime Minister David Cameron, Pakistani Prime Minister Nawaz Sharif, Russian President Vladimir Putin and former Chinese leaders.

The files also reveal the names of Egypt's former President Hosni Mubarak, former Libyan leader Muammar Gaddafi and Syria's President Bashar al-Assad.

Chinese leader Xi Jinping, Malaysian Prime Minister Najb Razak, former Chinese PM Li Peng, South Africa President Jacob Zuma and former UN secretary-general Kofi Annan also feature in the list through their children or close relatives.

The papers showed British PM David Cameron's father had used offshore techniques to avoid UK taxes.

Apart from political bigwigs, world's most well known entertainment personalities also figure in the list. These include Bollywood legend Amitabh Bachchan and martial arts star Jackie Chan. Reports said Bachchan's daughter in law and Bollywood queen Aishwarya Rai and as many as 500 Indian elite were on the list.

How was the document leaked and who did it?

The huge stash of documents was leaked to German newspaper Sueddeutsche Zeitung. The newspaper shared it with the International Consortium of Investigative Journalists, leading to the papers being made accessible to as many as 107 media organisations across 76 countries.

The mammoth data pile is being analyzed by journalists at these organisations. The identity of the source who lifted the chunk of data and leaked to the media is not known.

"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," Gerard Ryle, director of the International Consortium of Investigative Journalists (ICIJ) said.

ICIJ director Ryle told the Wired the Panama Papers data leak started in 2014. It started when an source approached German newspaper Suddeutsche Zeitung saying they wanted to make the crimes involving the law firm public.

The newspaper's reporter Bastian Obermayer worked on the leak, communicating with the whistleblower though encrypted chat for months.

"Over time we got more and more until we had all 11.5 million documents," Ryle said.

Obermayer did not say how the leaker sent hundreds of gigabytes or even terabytes of information at a time. "I learned a lot about making the safe transfer of big files," he, however, says.

Once the data dump, which was enough to fill 600 DVDs, was received in full, ICIJ's developers built a two-factor-authentication-protected search engine for the leaked documents. Wired says.

And then they brought several media outlets in different continents on board, setting off the concerted effort to search through the millions of documents.

Why?

The source of the leak insisted there was no financial motive or other plans to make gains from the leak. Obermayer and his co-authors wrote in Suddeutsche Zeitung the source did not want anythign else in return except some measures that ensured hius safety.

"We're not WikiLeaks. We're trying to show that journalism can be done responsibly," ICIJ director Ryle said. 

Meanwhile, Mossack Fonseca said they did not do anything wrong, adding that it was the victim of a campaign against privacy. In a statement on its website on Monday, the law firm said the media reports "misrepresented the nature of our work."

"We routinely resign from client engagements when ongoing due diligence and updates to sanctions lists reveal that a beneficial owner of a company for which we provide services is compromised," it said.