BEIJING, Jan. 19 -- China on Monday described allegations that its spies stole key information on the F-35 Lightening II fighter jet as "groundless and unproven."

Foreign Ministry spokesman Hong Lei made the remarks at a daily press briefing in response to a report in German magazine Der Spiegel, which cited documents disclosed by former U.S. intelligence contractor Edward Snowden, that Chinese cyber spies stole "huge volumes" of sensitive military information relating to the plane.

"The allegations are totally groundless and unproven," said Hong.

China has been the victim of cyber attacks and cyber security is a common challenge of every country, Hong said.

He said it was extremely difficult to confirm the sources of cyber attacks as they usually involved several countries and were hard to backtrack.

"I don't know what proof they hold to back up their accusations," said Hong.

"We, on the other hand, do have documents that show a certain country has a dishonorable record on cyber security," the spokesman said.

He called for an end to finger pointing and urged nations to fight cyber hacking together.