How many journalists does it take to get through 11.5 million documents about 214,000 companies that reveal how the world’s rich use shell accounts to evade national regulations and taxes? Try 370, from more than 100 news organisations in 70 countries.

This morning’s Panama Papers investigation — based on a massive leaked trove of documents about the clients of Mossack Fonseca, a Panama law firm that sells shell companies to the world’s wealthy — is published in Australia by the ABC’s Four Corners, Fairfax’s Financial Review, and the Guardian Australia. It is the latest in a string of global investigations based on leaked documents co-ordinated through the Washington-based International Consortium of Investigative Journalists.

The consortium is headed by former Fairfax investigative gun Gerard Ryle, who headed to America to head the philanthropically funded centre in 2011. Its previous investigations have similarly focused on the movements of global capital — something often too complex and international in nature to cover from just one newsroom or even one country. Ryle told Crikey this morning that sharing such investigations across media organisations brought local knowledge and expertise to bear on global stories of international relevance. But such collaboration does come with risks.

Keeping 370 journalists across 70 countries quiet about this kind of story is tricky. No one broke the agreed-upon publication time, Ryle says — at least not on this occasion.

“Last time we did this, one of our partners went ahead an hour before anyone else. The very first time, someone tweeted in Portuguese a week before. We’ve had scares. And some of the partners were teasing the story a bit too blatantly.

“But you’ve got to use common sense on this — you can’t micromanage everyone.”

In many ways, the ICIJ’s model of bringing in hundreds of media partners on major stories goes against the inbuilt habits of journalists, who are used to guarding their secrets until the big reveal and wherever possible scooping the competition.

But it works, Ryle says. “I spent nearly all of my career keeping secrets from people and not telling anyone around me. Now know there’s a whole new way of doing things. And as long as you don’t have too much competition in the country, there’s plenty of room for everyone.

“If you’re doing a story that leads you to Brazil or Paraguay, and you’ve got a reporter on the team from those countries, you just get so much more material.”

Not everyone is a subscriber to the ICIJ’s view of journalism. In Australia, News Corp has partnered with others from time to time — notably with Four Corners. But given the other two major media outlets in Australia (Fairfax and the ABC) are involved, News Corp’s Australian titles are conspicuous in their absence from the list of partner publications.

Ryle spent much of his career at Fairfax, so it’s no wonder introductions there were easily made. But he says convincing publications to come on board isn’t always easy. For example, he says, he approached The Wall Street Journal in the past, but the News Corp paper was hesitant. “They didn’t want to work in a collaborative way,” he said.

The ICIJ is not as open with its data as, say, WikiLeaks. Parts of the Panama Papers will be released in May, the ICIJ says, but they will not be published in their entirety. “We don’t want to dump documents on the internet, we want to do journalism,” Ryle said. “Our philosophy from day one has been to reclaim the journalism. We apply public interest tests to the documents.”

“We will eventually release more material.”

It would be impossible to do a global investigation like the Panama Papers without a high measure of goodwill across organisations. In 2013, German paper Suddeutsche Zeitung was one of the partners in the ICIJ’s investigations into Offshore Leaks, Lux Leaks and Swiss Leaks. A year ago, someone who had read its coverage got in touch about leaking the information released this morning. Suddeutsche Zeitung decided to share this with the ICIJ, which in turn brought on many of its partners to investigate.

The source of the initial leak is not known to the papers involved, The Guardian wrote today. But they’re confident the documents are genuine.

Half the ICIJ’s staff are data engineers — they worked out a way to index and catalogue the papers on secure servers for the participating journalists to view. Those journalists were then invited into a virtual newsroom, with live chatting capabilities. The ICIJ tried to encourage journalists to be very open with each other. “We encouraged them from day one that if they saw something of interest in their own countries [in the leaked papers], they should tell their colleagues about it.”

The vibe was good, says the AFR’s Neil Chenoweth, who worked on the story. “[There’s] a lot of collegiality in this,” he told Crikey. Writing on the ABC this morning, Four Corners’ Marian Wilkinson described turning up to Panama to try to get answers from Mossack Fonseca.

“With producer Ali Russell and crew Ron Foley and Geoff Krix, I met up with some 25 journalists from around the world who had been working like us for months.

“We swapped notes on our discoveries of a maze of covert financial dealings by drug dealers, former intelligence officers, businessmen tied up in the giant Petrobas scandal that is threatening the Brazilian President, players in the FIFA corruption case and much more.”

The journos went together to Mossack Fonseca’s headquarters to try to get answers (as shown in this video by Four Corners).

“By this point, we’ve worked with the organisations before, so there’s a huge level of trust,” Ryle said. “What was different from previous investigations was we had quite a number of in-person meetings.”

Still, there were competing priorities at times. One of the biggest was the publication date — which was the only restriction the ICIJ puts on reporters accessing the papers.

“You’re trying to please as many people as possible,” Ryle says. But different countries have different days when they publish these kind of things. The Australian media like to make a splash on a Monday, while the Sunday papers in the United States carry the biggest scoops.

A day was decided on well in advance, but it had to be changed when German publishers said it would clash with local elections in Germany.

“In the end, we decided to go when we did to suit the German parties — they bought us the data after all,” Ryle said. But even Suddeutsche Zeitung doesn’t carry the scoop in its first edition today — it had to wait on the second to not breach the ICIJ’s deadline. That’s an expensive proposition for a paper, Ryle admits. Convincing them, he says, took “a lot of arm wrestling”.

Today’s investigation is one of the largest to come out of the ICIJ. But Ryle says the organisation, which is entirely philanthropically funded, very much survives from pay cheque to pay cheque. “We have to keep showing we can make it work,” Ryle said. “At the moment we’re relying on the generosity of people like Graeme Wood.” Wood, the Australian founder of Wotif, is one of the ICIJ’s biggest donors.