China newspaper rejects J-20 stealth jet claim
A Chinese state newspaper has dismissed reports that technology for Beijing's J-20 stealth jet came from a US fighter downed in 1999 during the Kosovo war.
Croatia's military chief of staff at the time claims Chinese agents recovered parts of a F-117 Nighthawk stealth jet shot down over Serbia.
The Global Times quoted a top Chinese test pilot as saying the J-20 was a "masterpiece" of home-grown innovation.
An unnamed defence official described the claim as a foreign media "smear".
"It's not the first time foreign media has smeared newly-unveiled Chinese military technologies. It's meaningless to respond to such speculations," the official, from the Ministry of National Defence, told the Global Times.
A top test pilot, Xu Yongling, told the newspaper that the F-117 technology was already "outdated" even at the time it was shot down, and could not be applied to a next-generation stealth jet.
A write-up of the Global Times article was also carried by the website of the People's Daily, the Communist Party paper.
But there has been little formal comment from Chinese officials on the stealth jet since its test-flight on 11 January - while US Defence Secretary Robert Gates visited Beijing.
China says it expects the jet to be operational some time between 2017 and 2019. Currently, the US is the only nation with a fully operational stealth plane, the F-22 Raptor.
Nighthawks were the world's first stealth fighters - planes that are almost invisible to radar.
After the F-117 was shot down in 1999 during a Nato bombing, military officials and experts say they believe that some of the parts found themselves in Chinese hands, which allowed China to replicate them to develop similar technologies.
The reports come at a time of heightened sensitivities. On Monday, a US engineer who sold military secrets to China was sentenced to 32 years in prison.
Indian-born Noshir Gowadia was found guilty of passing on information which helped China to design a stealth cruise missile.
Meanwhile, some analysts have claimed the J-20 prototype is a sign of military strength that will worry the US government, but the Pentagon has played down concerns over the fighter.
China's official military budget quadrupled between 1999 and 2009 as the country's economy grew. In 2010 it stood at $78bn (£50bn).
But the US has by far the largest defence budget in the world at just over $700bn.