BERLIN (AP) ― U.S. intelligence agencies hacked into the email servers of Chinese tech giant Huawei five years ago, around the time concerns were growing in Washington that the telecommunications equipment manufacturer was a threat to U.S. national security, two newspapers reported Saturday.

The National Security Agency began targeting Huawei in early 2009 and quickly succeeded in gaining access to the company’s client lists and email archive, German weekly Der Spiegel reported, citing secret U.S. intelligence documents leaked by former NSA contractor Edward Snowden. The New York Times also published a report Saturday about the documents.

Huawei objects to activities that threaten network security, said William B. Plummer, the company’s vice president of external affairs.

“Huawei has declared its willingness to work with governments, industry stakeholders and customers in an open and transparent manner, to jointly address the global challenges of network security and data integrity,” Plummer said in an email. “The information presented in Der Spiegel and the New York Times article reaffirms the need for all companies to be vigilant at all times.”

Among the people whose emails the NSA was able to read were Huawei president Ren Zhengfei, Der Spiegel said.

The operation, which Der Spiegel claims was coordinated with the CIA, FBI and White House officials, also netted source codes for Huawei products. One aim was to exploit the fact that Huawei equipment is widely used to route voice and data traffic around the world, according to the report. But the NSA was also concerned that the Chinese government itself might use Huawei’s presence in foreign networks for espionage purposes, it said.

In response to the Der Spiegel report, NSA spokeswoman Vanee Vines said the agency doesn’t comment on specific alleged activities. She reiterated the NSA’s position that its activities are aimed only at “valid foreign intelligence targets in response to intelligence requirements.”

“In addition, we do not use foreign intelligence capabilities to steal the trade secrets of foreign companies on behalf of ― or give intelligence we collect to ― U.S. companies to enhance their international competitiveness or increase their bottom line,” Vines said in a statement emailed to the Associated Press.

In 2012, the House Intelligence Committee recommended that Huawei be barred from doing business in the U.S., citing the threat that its equipment could enable Chinese intelligence services to tamper with American communications networks.