The US Justice Department is suing former CIA contractor-turned whistleblower Edward Snowden.

He has published a new book, 'Permanent Record', which the US claims is in violation of Central Intelligence Agency (CIA) and National Security Agency (NSA) non-disclosure agreements.

The book reveals how he helped to build this system and why he was moved to expose it, according to its synopsis.

The lawsuit alleges Mr Snowden published his book without submitting it to the agencies for pre-publication review, in violation of "his express obligations under the agreements he signed."

It also alleges that he has given public speeches on intelligence-related matters, also in violation of his agreements.

However, the United States lawsuit does not seek to stop or restrict the publication or distribution of 'Permanent Record'.

Instead, it wants to take all the proceeds earned by Mr Snowden because of his "failure to submit his publication for pre-publication review in violation of his alleged contractual and fiduciary obligations".

The lawsuit also names the corporate entities involved in publishing the book as defendants.

The US Justice Department says it is suing the publisher "to ensure that no funds are transferred to Snowden, or at his direction, while the court resolves the United States' claims."

Copies of Edward Snowden's new book Permanent Record' are offered for sale | Image: Jorg Carstensen/DPA/PA Images

Mr Snowden is living outside of the United States.

In 2013, he was charged with espionage and was granted asylum by Russia, after instigating a series of leaks on mass surveillance in America and around the world.

Snowden, a former CIA technician who was contracted for the NSA, admitted his role in leaks to The Guardian and The Washington Post newspapers - saying the public needed to decide whether the programmes were right or wrong.

"I'm not going to hide," Mr Snowden said in June 2013. "Allowing the US government to intimidate its people with threats of retaliation for revealing wrongdoing is contrary to the public interest."

US Assistant Attorney-General Jody Hunt said: "Edward Snowden has violated an obligation he undertook to the United States when he signed agreements as part of his employment by the CIA and as an NSA contractor.

"The United States' ability to protect sensitive national security information depends on employees' and contractors' compliance with their non-disclosure agreements, including their pre-publication review obligations.

"This lawsuit demonstrates that the Department of Justice does not tolerate these breaches of the public's trust.

"We will not permit individuals to enrich themselves, at the expense of the United States, without complying with their pre-publication review obligations."

The US adds that its claims are allegations only, and that there has been no determination of liability.

The book remains on sale in bookshops and online retailers.