The anti-secrecy group WikiLeaks said it would begin publishing more than five million emails Monday from a US-based global security think tank, apparently obtained by hackers.

In its latest high-profile disclosure, WikiLeaks said in a statement it had acquired access to a vast haul of internal and external correspondence of Strategic Forecasting Inc (Stratfor), based in Austin Texas.

Stratfor describes itself as a subscription-based provider of geopolitical analysis with an intelligence-based approach to gathering information.

WikiLeaks' founder, Julian Assange told Reuters: Here we have a private intelligence firm, relying on informants from the US government, foreign intelligence agencies with questionable reputations, and journalists.

What is of grave concern is that the targets of this scrutiny are, among others, activist organizations fighting for a just cause.

Stratfor's chief executive officer and founder, George Friedman warned on January 11 that emails had been stolen but said the thieves would be hard pressed to find anything significant.

God knows what a hundred employees writing endless emails might say that is embarrassing, stupid or subject to misinterpretation... As they search our emails for signs of a vast conspiracy, they will be disappointed.

The source of the emails was not disclosed, but the publication follows the hacking of the company's computer servers last December by individuals claiming to be linked to the Anonymous cyber-activist group.

After Stratfor's computers were hacked into at least twice last December, the credit card details of more than 30,000 subscribers to Stratfor publications were posted on the Internet, including those of former US secretary of state Kissinger and vice president Dan Quayle.

An FBI investigation is already underway into the hack last December. Friedman said his staff were cooperating with the FBI in the investigation.

Of course we have relationships with people in the U.S. and other governments and obviously we know people in corporations, and that will be discovered in the emails. But that's our job.

We are what we said we were: an organization that generates its revenues through geopolitical analysis. At the core of our business, we objectively acquire, organize, analyze and distribute information.

WikiLeaks released secret video footage and thousands of U.S. diplomatic cables about the wars in Iraq and Afghanistan in 2010, infuriating the U.S. government.

Australian-born Assange, 40, is currently under house arrest in Britian and fighting extradition to Sweden for questioning over alleged sex crimes.

(Reporting by Stephen Grey; editing by Philippa Fletcher)

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