The mechanics of PRISM are still little-understood, but initial reports described it as being able to draw data directly from the servers of Silicon Valley's biggest firms.
The revelation that the U.K. eavesdropping agency GCHQ also drew on the data sparked concerns that British spies were using PRISM to bypass U.K. rules on domestic espionage.
But a statement issued by the committee Wednesday said it had seen no evidence of wrongdoing.
Copyright 2013 The Associated Press.
Photo: File photo dated 23/01/04 of the Government Communication Headquarters (GCHQ) as the Intelligence and Security Committee, which oversees the work of the intelligence agencies.