Der Spiegel, said that Germany’s Federal Intelligence Agency (BND) sent "massive amounts" of data to the NSA.
The report, which was based on documents leaked by former NSA contractor Edward Snowden, revealed that about 500 million pieces of phone and email communications metadata collected by the NSA in Germany last December was apparently provided by the BND.
German opposition party leaders, such as Hans-Christian Stroebele of the Green Party, have expressed outrage and called for full investigations into the nature and scope of the information communicated.
But the BND claims it sent the metadata legally and that it did not include information about German citizens.
Germany and the United States will start negotiations this month on an agreement not to spy on each other, a senior German official has said.
Chancellor Angela Merkel's chief of staff, Ronald Pofalla, said on Monday that such an agreement can set a framework for future activities of western spying agencies, the Associated Press reported.
Pofalla, who is responsible for coordinating the various intelligence services in Germany, made the remarks after he testified to a parliamentary committee on the government's role in the US National Security Agency (NSA) scandal.
Pofalla said the pact would include economic intelligence gathering and might limit NSA operations such as PRISM.
PRISM, a surveillance system launched in 2007 by the NSA, allows the organization to receive emails, video clips, photos, voice and video calls, social networking details, logins and other data held by a range of US internet firms.
Pofalla noted that the US had offered talks on a no-spy agreement, which showed that the US was serious about adhering to German law on German soil.
Thomas Oppermann, an opposition Social Democrat who chairs the committee, called the offer a "face-saving confession" by Washington which in itself showed that surveillance had taken place.
A report, published on August 8 by German weekly magazine