BEIJING - Chinese skating authorities denied allegations of age-limit violations on Tuesday against 2006 Winter Olympic pairs silver medalists Zhang Dan and Zhang Hao - among others - but said further investigations are under way.

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"The Chinese Skating Association (CSA) opposes all kinds of age cheating. According to our investigation, the ages of Zhang Dan and Zhang Hao that were registered for international events were their real ages," it said in a statement.

The Associated Press reported on Tuesday that nine Chinese figure skaters may have violated competition age-limit rules, by competing when they were either too young or too old.

Other skaters facing allegations include reigning world junior champion pair Sui Wenjing and Han Cong, as well as women's singles skaters Geng Bingwa and Xu Binshu.

AP found discrepancies when comparing a list of birthdates published on the CSA's website to those listed on the athletes' International Skating Union (ISU) bios.

According to ISU rules, skaters must be 15 by the preceding July 1 to compete at an Olympics or senior world championships, and 14 for other senior-level international competitions, such as the Grand Prix final.

The world's skating governing body imposed the age limits in 1996 to protect young athletes from serious injury.

AP said that the information on the CSA website showed that Zhang Dan was born on Oct 4, 1987, which means she was only 14 when she and Zhang Hao competed at the 2002 Salt Lake City Winter Olympics and the World Championships the same year. The pair finished 11th at that Olympics and ninth at the worlds. The website information also showed that Zhang Hao was too old for the 2003 Junior World Championships, where the pair won the title.

On the ISU bios, Zhang Dan was born on Oct 4, 1985, while her partner was born on July 6, 1984, which means they could meet the age limitation for all the events.

The CSA said the discrepancies were caused by mistakes in the registration process.

"For the questions raised by some media about the age differences, our primary investigation found that they were caused by mistakes during the registration and information collecting process for our websites," the CSA said.

"We have paid great attention to it and investigations are still going on."

The ISU and the International Olympic Committee have been aware of the case and asked the skating authorities for more information, AP reported.