The NSA began targeting Huawei in early 2009 and quickly succeeded in gaining access to the company’s client lists and email archive, Der Spiegel reports.

US 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 US national security, a report says.

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 on Saturday, citing secret US intelligence documents leaked by former NSA contractor Edward Snowden.

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

The operation, which Der Spiegel claims was co-ordinated 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 2012, the House Intelligence Committee recommended that Huawei be barred from doing business in the US, citing the threat that its equipment could enable Chinese intelligence services to tamper with American communications networks.

Huawei didn’t immediately respond to a request for comment late on Saturday.

In January, the company rejected a previous Der Spiegel report claiming that its equipment was vulnerable to hacking.

The magazine had reported that the NSA was able to install secret “back doors” in telecoms equipment made by Huawei and other companies.

Der Spiegel’s latest report claims the NSA also targeted top Chinese officials, such as former President Hu Jintao, as well as ministries and banks.