Edward Snowden, the US whistleblower who leaked information from the US National Security Agency (NSA) and British intelligence agency in 2013, will publish his memoir "Permanent Record" on September 17.

Snowden, a former employee at the NSA, wanted to describe his crisis of conscience that lead to him leaking the information, German publisher S. Fischer Verlag, said.

Snowden, 36, is living in Russia, where he was granted asylum. After leaking the NSA information, he left the US and became stranded at Moscow airport when his passport was cancelled.

Until the leaks, the public did not know the extent of the surveillance of the NSA and its British counterpart GCHQ. Snowden's information led to the wider use of encryption technology and to an overhauling of data transfer practices from Europe to the US.