China's prototype stealth fighter, unveiled earlier this month, was not based on stolen foreign technology but rather a "masterpiece" of homegrown innovation, a state-run newspaper has claimed.
The first test-flight of China's Chengdu J-20 "stealth" fighter came on the same day that Robert Gates, the US defence secretary, made a key visit to Beijing, raising fears that China's defence capabilities were modernising faster than previously thought.
China's apparent advances in stealth technology, first invented in the US in the 1970s, were later linked to reports that Chinese agents had bought up wreckage of an American F-1117 Nighthawk fighter that was shot down over Serbia in 1999.
But China's state-run Global Times newspaper, a sister publication of the Communist Party mouthpiece The People's Daily, quoted Chinese military officials dismissing the claims as a Western "smear campaign".
A senior Chinese test pilot, Xu Yongling, told the paper that J-20 possessed advanced supersonic cruise ability and other "breakthrough" features of a "fifth generation" fighter, such as America's F-22 Raptor.
"Unlike previous fighters such as the J-7 and J-8, which drew on the merits of aircraft from other countries, the J-20 is a masterpiece of China's technological innovation," Mr Xu was quoted as saying.
China's nationalist tabloid media frequently likes to heap praise on the country's growing technological prowess, holding up its engineering achievements as examples of Beijing's rising power and prestige on the world stage.
Independent aviation defence analysts are more sceptical of China's claims for the J-20 which experts say is a "kludge", or hotchpotch, of different American and Russian aircraft and has very limited stealth capabilities.
However James Hardy, Asia-Pacific editor of Jane's Defence Weekly, said that it was "unlikely" that China had gleaned much from the wreckage of the F-117, which used technologies from the 1970s, but had instead developed the J-20 from old Russian technology.
"When you see it [the J-20] you will realise that at least half of this aeroplane is of Russian design," a Russian industry source told Jane's this month, "There is practically no other place that they could have come up with a platform for a stealthy or blended body design in - what is even for them [the Chinese] - such a short period of time."
The claims came a day after a former B-2 stealth bomber engineer was jailed for 32 years on Monday by a US court for selling military secrets to China.
Noshir Gowadia, 66, made profits of at least $110,000 (€80,800) by selling classified engine technology that China needed for its design of a stealth cruise missile that could evade infra-red detection, the Honolulu court heard.
Gowadia, an engineer with the Northrop Grumman Corporation between 1968-88 who worked on the B-2 design, made repeated trips to China between 2003 and 2005 providing "defence services" to China's cruise missile programme as a freelance consultant.