In an interview with Forbes, conducted just before WikiLeaks released the US embassy cables, Assange says the site has a "megaleak" with "either tens or hundreds of thousands of documents depending on how you define it" on a "big US bank".

The release "will give a true and representative insight into how banks behave at the executive level in a way that will stimulate investigations and reforms, I presume".

Assange compares the leak to Enron. "Why were these so valuable? When Enron collapsed, through court processes, thousands and thousands of emails came out that were internal, and it provided a window into how the whole company was managed. It was all the little decisions that supported the flagrant violations."

He says the bank documents will show a similar a pattern. "Yes, there will be some flagrant violations, unethical practices that will be revealed, but it will also be all the supporting decision-making structures and the internal executive ethos that comes out, and that's tremendously valuable."

He continues: "You could call it the ecosystem of corruption. But it's also all the regular decision making that turns a blind eye to and supports unethical practices: the oversight that's not done, the priorities of executives, how they think they're fulfilling their own self-interest. The way they talk about it."

Assange claims the documents show that "it's clear there were unethical practices, but it's too early to suggest there's criminality. We have to be careful about applying criminal labels to people until we're very sure."

After high profile government-related leaks, the expected bank disclosure is set to be the just the beginning of an assault on business. Assange says WiliLeaks has information on firms in the energy and pharmaceutical industries but "of the commercial sectors we've covered, finance is the most significant".

An Interview With WikiLeaks' Julian Assange - Forbes