NINE in 10 emails intercepted by the US National Security Agency (NSA) were from “ordinary” US citizens and foreigners who were not legally targeted, an investigation has found.

The Washington Post study published at the weekend revealed that over 10,000 email account-holders who were not targeted still had their daily lives catalogued and recorded.

“Stories of love and heartbreak, illicit sexual liaisons, mental health crises, political and religious conversions, financial anxieties and disappointed hopes” were all hoovered up by the infamous spy agency.

The finding is embarrassing for Washington after relations soured with Germany when it arrested one of its citizens last week on charges of spying for the US.

German President Joachim Gauck said if the allegations were true “then it really has to be said: That’s enough now.”

German Interior Minister Thomas de Maiziere said he “expected quick and clear statements from the US,” but intelligence agencies have declined to comment.