By Song Shengxia

Chinese defense officials and military analysts insisted Monday that the country's J-20 stealth fighter jet is a result of technological innovation, refuting a report that alleges the aircraft was developed out of technology gleaned from a downed US fighter.

A Croatian admiral who served during the Kosovo War told the AP on Sunday that China formulated the technology for its J-20 jet from a F-117 Nighthawk stealth fighter that was shot down over Serbia in 1999.

"At the time, our intelligence reports told of Chinese agents criss-crossing the region where the F-117 disintegrated, buying up parts of the plane from local farmers," Admiral Davor Domazet-Loso was quoted as saying. "We believe the Chinese used those materials to gain an insight into secret stealth technologies."

An official at the Ministry of National Defense who declined to be named told the Global Times that "it's not the first time foreign media has smeared newly unveiled Chinese military technologies. It's meaningless to respond to such speculations."

China successfully debuted the J-20 in Chengdu, Sichuan Province, earlier this month. The test flight coincided with US Defense Secretary Robert Gates' visit to Beijing, but he was assured the timing was just a coincidence.

Following the successful test flight, speculations and assessments of Beijing's military advancement could be heard throughout the world.

Xu Yongling, one of China's top test pilots, told the Global Times that the J-20 possesses an advanced supersonic cruise ability and powerful air mobility that are technological breakthroughs for the country.

"Different from previous fighters such as the J-7 and J-8, which drew on the merits of aircrafts from other countries, the J-20 is a masterpiece of China's technological innovation," Xu said, comparing the stealth jet to the US Air Force's F-22 Raptor stealth jet and Russia's first stealth fighter, the Sukhoi T-50.

Xu said it would have been impossible for China to glean technology from the US' F-117, whose stealth technology lags far behind fourth-generation fighters and was regarded as "outdated" even at the time when it was reportedly shot down.

And as for the radiation-absorbent, exterior coating technology adopted by the F-117, Xu said it would be hard to copy that technology from the wreckage due to its complicated production process.

Developed in the 1970s and commencing service in 1983, the F-117 Nighthawk was the world's first stealth fighter - nearly invisible to radar.

In March 1999, during NATO's aerial bombing of Serbia in the Kosovo War, a Serbian anti-aircraft missile shot one of the Nighthawks down. An editorial published by the Taiwan-based China Times on Saturday said that the shooting down of the F-117 could have provided an excuse for Taiwan to reform its military.

Parts of the downed F-117 wreckage - including the left wing with the US Air Force insignia, the cockpit canopy, the ejection seat, the pilot's helmet and a radio - are exhibited at Belgrade's aviation museum, according to an AP report.

"I don't know what happened to the rest of the plane," said Zoran Milicevic, deputy director of the museum, according to the AP. "A lot of delegations visited us in the past, including the Chinese, Rus-sians and Americans ... but no one showed any interest in taking any part of the jet."

Wang Yanan, an associate editor in chief at Aerospace Knowledge magazine, told the Global Times that the F-117 could hardly have inspired the development of the J-20, due to the design differences between the two generations of fighters. He added that it is worthless to take an interest in obsolete technology for developing more state-of-art technologies.

"Despite being dubbed a stealth fighter, the F-117 functioned as a bomber because of its low speed and limited air attacking abilities, while the J-20, more resembling the F-22, is designed to have a powerful air attacking capability with a fast flying speed," Wang said.

Responding to the accusations about China's stealing of new technologies, Wang conceded that, as a forerunner for new technologies, the US can only provide a reference point for other countries but will never leak any details about the technologies, leaving many countries to develop weapons on their own or buy them from another country.

The US has, in recent years, stepped up its offensive against what it calls "Chinese tech spying." The FBI increased its agents assigned to counter alleged Chinese espionage from 150 in 2001 to more than 350 in 2007, USA Today reported.

Separately, Noshir Gowadia, an Indian-born former B-2 bomber engineer convicted of helping China design a stealth cruise missile, was due to be sentenced in court today.

Li Daguang, a Beijing-based military analyst, told the Global Times that such accusations are groundless and originate from envy and wariness of China's technological advancements.

"China not only has the freedom to develop high-end technologies but also the capability to develop them independently," he said.

Zhu Shanshan and Huang Jingjing contributed to this story