Secret service agents in Paris are snooping on internal communications in a scheme similar to the one exposed by National Security Agency whistleblower Edward Snowden in the US, according to a damning exposé in the French press.

Despite slamming the mass surveillance by Washington of Americans and of US allies, France is guilty of the same subterfuge, according to Le Monde.

France's external intelligence agency, the General Directorate for External Security (DGSE), monitors all communications between French citizens at home and abroad and stockpiles the data, the Le Monde investigation claimed.

"[DGSE] systematically collects electromagnetic signals issued by computers and phones in France as well as [communication] flows between French abroad," the paper's investigation team said.

"All emails, text messages, telephone records and logs in to Facebook, Twitter are stored for years."

The system, dubbed the French Big Brother, does not record the content of communications but harvests their meta-data including length of message, transmission site and date.

"The same happens for emails (with the possibility of reading their subject), SMS, fax and everything that passes through Google, Facebook, Microsoft, Apple, and Yahoo!" Le Monde wrote.

Because of the huge amount of data stored in the basement of the DGSE HQ in Paris' Boulevard Mortier, French secret services are able to "draw a sort of intimate journal of everyone's phone and computer activity", the newspaper continued.

The DGSE shares the data with seven other national intelligence agencies, including the Directorate of Military Intelligence and the Central Directorate of Interior Intelligence.

The surveillance system was described not as illegal by the newspaper but as "a-legal", ie it operates outside any legal system.

The French government led by President Francois Hollande expressed outrage at the US over reports that he NSA spied on its European allies.

Paris called for a suspension of negotiations between the US and the EU over a new major trade agreement after the revelations by Snowden suggesting that the NSA bugged EU diplomatic offices in Washington and infiltrated its computer network were published by Der Spiegel newspaper.