US intelligence and law enforcement officials say they've been aware since the end of last year of a security breach at the CIA and are focusing on contractors as the likeliest source of documents being passed on to WikiLeaks detailing the agency's hacking tools.

The officials told Reuters that they believed documents published by WikiLeaks yesterday about CIA techniques used between 2013 and 2016 are authentic.

The documents show that CIA hackers could get into Apple iPhones, Google Android devices and other gadgets in order to capture text and voice messages before they were encrypted.

The White House says that President Donald Trump is "extremely concerned" about the CIA security breach that led to the Wikileaks release, and the Administration will be tough on leakers.


"Anybody who leaks classified information will be held to the highest degree of law," spokesman Sean Spicer told reporters.

A person familiar with Wikileaks' activities said Wikileaks has had the CIA hacking material for months, and that the release of the material was in the works "for a long time".

A Congressional official said that the US House of Representatives Intelligence Committee has begun asking questions about the WikiLeaks disclosures.

In Germany , the chief federal prosecutor's office said that it would review the Wikileaks documents because some suggested that the CIA ran a hacking hub from the US consulate in Frankfurt.

Chancellor Angela Merkel is scheduled to visit Washington on March 15 for her first meeting with Trump, who has sharply criticised Berlin for everything from its trade policy to what he considers inadequate levels of military spending.

The Wikileaks documents may also complicate bilateral intelligence ties that have just begun to recover after a series of scandals, including news in 2013 that the US National Security Agency had bugged Merkel's phone. The Frankfurt consulate was investigated by German lawmakers after that incident.

Merkel told lawmakers last month she did not know how closely Germany's spies cooperated with their US counterparts until 2015 when former NSA contractor Edward Snowden revealed the BND spy agency had for years passed on information to the NSA about European companies and politicians.

- Reuters, AAP