An official revealed that nine-year-old Lin Miaoke lip-synched her performance at the Beijing opening ceremony. (Zhou Liang/Xinhua/Associated Press)

China's flamboyant Olympics opening ceremony on Friday has lost some of its lustre, following an official's revelation of lip-synching at the over-the-top event.

In an interview with Beijing Radio, Chen Qigang, the ceremony's chief music director, admitted that the pig-tailed, nine-year-old girl in a red dress shown singing was actually lip-synching Ode to the Motherland to audio of another girl, deemed not as pretty but with a lovelier voice.

"After several tests, we decided to put Lin Miaoke on the live picture, while using [seven-year-old] Yang Peiyi's voice," Chen told the radio station.

"The reason for this is that we must put our country's interest first," he added. "We had to make that choice. It was fair both for Lin Miaoke and Yang Peiyi … We combined the perfect voice and the perfect performance."

Yang Peiyi, a seven-year-old, recorded the song that Lin Miaoke appeared to be singing. (CCTV)

This follows the revelation, in April, that Luciano Pavarotti lip-synched and his backing orchestra mimed their performance at the opening ceremony of the 2006 Torino Winter Olympics.

It was among the famed Italian tenor's last major public performances. He was diagnosed with pancreatic cancer later that year and died in September 2007.

"Pavarotti's great career therefore ended with a virtual performance, something sad but inevitable," his longtime conductor and pianist Leone Magiera wrote in the book Pavarotti Visto da Vicino (Pavarotti Seen from Up Close).

The news of the Beijing lip-synching also comes amid confirmation that one of the myriad fireworks displays during the opening ceremony — the 29 "footprints" segment — was pre-recorded.

Vice-president Wang Wei of the Beijing organizing committee said Tuesday that broadcasters were supplied tape of the computer-enhanced segment.

"Previously recorded footage was provided to the broadcasters for convenience and theatrical effects — as in many other big events," Wang said.

"On the day of the ceremony there were actual footprints of fireworks from the south to the north of the city," he said. However, worries about poor visibility outside the stadium and possible danger to the helicopter crew needed to capture the aerial footage were among the reasons cited for creating the segment.

NBC, the U.S. broadcaster of the Olympics, said that its opening ceremony hosts, Bob Costas and Matt Lauer, had noted on-air on Friday that the display in question was cinematic.

Officials estimate that more than one billion people around the globe tuned into the lavish ceremony.

With files from the Associated Press