China’s cyber spies have successfully hacked into the private emails of top U.S. officials, according to reports obtained by NBC News.

The report stated that certain top Obama administration officials private emails has been compromised, this report was confirmed by a senior U.S. intelligence official.

The top-secret documents obtained by NBC also revealed that infringement into private emails by the Chinese has been going on since April 2010.

According to a senior U.S. intelligence official the Chinese first hacked a top private email – codenamed “Dancing Panda”, then “Legion Amethyst”- before they were detected in April 2010, according to a 2014 briefing by a top secret NSA official. Although at the time of this briefing, it was believed that the intrusion was still active.

Google claimed that the private gmail accounts of some top U.S. officials had been hacked, as the briefing also shows that private email accounts from other providers were compromised as well.

The Chinese cyber spies were unable to hack the U.S. government email accounts assigned to the officials because they were more secured, says the senior U.S. intelligence official.

The senior official claims the private emails of “all top national security and trade officials” were targeted.

The Chinese cyber spies also gathered the email address books of targeted officials, according to the documents obtained by NBC News. The Chinese Cyberspies cleverly harnessed the email address books by reconstructing and then exploiting the social networks by sending malicious malware to their friends and colleagues.

The former secretary of state Hilary Clinton was not spared in the Chinese cyber hacking spree, as the time period overlaps with her use of a private email account from January 21, 2009 to February 1, 2013. However, the names and ranks of the officials whose emails were actually hacked were not disclosed in the NSA briefing nor by the intelligence official.

Related Article: NSA Report: China Successfully Hacked 600+ American Targets in 5 Years

There was another NSA document that was leaked by Edward Snowden which revealed that in late 2010 China had attempted to spy on the emails of four top U.S. officials, including the then Joint Chiefs of Staff Chairman Adm. Mike Mullen and Chief of Naval Operations Adm. Gary Roughead. The document, posted on-line by Der Spiegel, claim that the Chinese spies had made several attempt to insert malicious software into their computers.

NBC News also claim in 2013 that prior to the 2008 U.S. presidential election, the Chinese cyber spies had actually targeted the presidential campaigns of the then Sen. Obama and Sen. John McCain in order to obtain confidential emails and policy papers, and they actually succeeded in hacking some emails, including private communication from McCain.

The NSA has declined to comment to these reports and findings. It was reported that the “Dancing Panda” campaign revealed in the 2014 NSA briefing paper was among more than 30 “intrusion sets” launched by China that the NSA and other intelligence units identified last year in classified documents. NBC News claim that those campaigns resulted in more than 600 successful hacks on target.