Updated

Chancellor Angela Merkel's chief of staff has testified to a parliamentary committee about alleged surveillance by the U.S. National Surveillance Agency, which has become a campaign issue ahead of Germany's September elections.

Lawmakers from the center-left opposition said Thursday's meeting of the Parliamentary Control Body — a closed-doors, cross-party committee that supervises German intelligence — made no progress in addressing allegations that the NSA conducted widespread surveillance and questions about what Germany's spies and government knew.

Merkel's chief of staff, Ronald Pofalla, is responsible for coordinating Germany's intelligence agencies. Committee member Michael Grosse-Broemer, a senior lawmaker with Merkel's party, said the hearing showed German intelligence kept to German law and that there's still no information beyond that of leaker Edward Snowden on alleged mass U.S. surveillance.