The US National Security Agency spied on French presidents Jacques Chirac, Nicolas Sarkozy and Francois Hollande according to WikiLeaks, citing top secret intelligence reports and technical documents.

The revelations were first reported in French daily publication Liberation and on news website Mediapart, which said the NSA spied on the presidents during a period of at least six years between 2006 until May 2012, the month when Mr Hollande took over from Mr Sarkozy.

WikiLeaks said the documents derived from directly targeted NSA surveillance of the communications of Mr Hollande(2012-present), Mr Sarkozy (2007-2012) and Mr Chirac (1995-2007), as well as French cabinet ministers and the French ambassador to the US.

The documents also contain the mobile phone numbers of numerous officials in the Elysee presidential palace including the direct mobile phone number of the president, WikiLeaks said.

The documents include summaries of conversations between French government officials on the global financial crisis, the Greek debt crisis, and the relationship between the Hollande administration and the German government of Angela Merkel.

Former NSA employee Edward Snowden created an uproar in Germany after he revealed that Washington had carried out large-scale electronic espionage in Germany and claimed the NSA had bugged Ms Merkel's phone.

"While the German disclosures focused on the isolated fact that senior officials were targeted by US intelligence, WikiLeaks' publication today provides much greater insight into US spying on its allies," WikiLeaks said.

This includes "the actual content of intelligence products deriving from the intercepts, showing how the US spies on the phone calls of French leaders and ministers for political, economic and diplomatic intelligence".

The French president's office was not immediately reachable for comment.

WikiLeaks said French readers could "expect more timely and important revelations in the near future.”

Last week, WikiLeaks published more than 60,000 diplomatic cables from Saudi Arabia and said on its website it would release 500,000 more in the coming weeks.