WikiLeaks founder Julian Assange has claimed a fresh "mega leak" will target a major US bank early next year.

Speaking to Forbes magazine, Mr Assange said he was ready to unleash tens of thousands of documents that could "take down a bank or two".

Comparing the documents to the emails that exposed Enron's dealings amid its collapse, the controversial Australian said an existing "big US bank" was the subject of a pending data dump.

Asked about any future leaks, he said: "Yes. We have one related to a bank coming up, that's a mega leak.

"It's not as big a scale as the Iraq material, but it's either tens or hundreds of thousands of documents depending on how you define it."

The interview was conducted in early November, before Sunday's publication of around 250,000 leaked US embassy cables from WikiLeaks that have caused consternation in Washington and capitals around the world.

As international investigations are fired up following the latest leak, Mr Assange has been offered residency in Ecuador with "no questions asked".

Earlier this month an international arrest warrant was issued against him on suspicion of rape and sexual molestation of two women in Sweden.

But he said the bank leak would "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".

"Usually when you get leaks at this level, it's about one particular case or one particular violation."

Amid the economic crisis a handful of too-big-to-fail US banks have come under scrutiny for their dealings, particularly with mortgaged-backed securities that helped fuel the meltdown.

Executives from Goldman Sachs and the now-defunct Lehman Brothers and Bear Stearns have been hauled before the US Congress to explain their banks' actions.

Mr Assange mentioned Goldman Sachs by name in the interview, but did not confirm the Wall Street giant will be the target of the leak.

Goldman recently agreed to a $US550 million settlement with the Securities and Exchange Commission to settle fraud charges.

Facing allegations of defrauding investors, the storied investment bank admitted it had made a "mistake" and given "incomplete" information to clients.

Mr Assange said "about 50 per cent" of the documents WikiLeaks holds relate to the corporate world.

Meanwhile, Ecuador's deputy foreign minister has offered the WikiLeaks founder residency.

"We are ready to give him residence in Ecuador, with no problems and no conditions," Kintto Lucas told the internet site Ecuadorinmediato.

"We are going to invite him to come to Ecuador so he can freely present the information he possesses and all the documentation, not just over the internet but in a variety of public forums."

Ecuador's leftist government is one of several in the region that has often been at odds with the US.

Mr Lucas said even though Ecuador's policy was not to meddle in the internal affairs of other countries, it was "concerned" by the information in the cables because it involved other countries, "in particular Latin America".

- AFP