Two female Chinese gymnasts, including a gold-medal favourite, might be too young to participate in the Beijing Olympics. Several online records and reports show He Kexin, the host nation's top competitor on uneven bars, and Jiang Yuyuan might not yet be 16, the minimum age for Olympic eligibility for gymnastics. Both were chosen for China's team last week.

On the website of the Chengdu Sports Bureau – Chengdu is the capital of Sichuan province in southwest China – a file dated January 2006 shows He as being born 1 January 1994. Most recently, a 23 May story in the China Daily newspaper, the official English language paper of the Chinese government, had He's age as 14. The newspaper story says: "The 14-year-old newcomer to the national team, who was recruited last year, has raised a lot of eyebrows recently after she broke two world records on the uneven bars in as many months."

The New York Times raised questions about the competitors' ages on Saturday, but Chinese officials provided it with copies of passports indicating both gymnasts are 16. However, in November last year, Liu Peng, the director of general administration of sport for China, said: "The 13-year-old uneven-bar gymnast, He Kexin, who defeated national team athlete Yang Yilin – she just won the bronze medal in the world championships – has demonstrated her ability."

To be eligible for the City Games in Wuhan, where Liu made his remarks, Chinese documents show athletes must be over 13, but under 15.

The spokesman for the Chinese Gymnastics Association, Zhang Peiwen, said: "Our squads were recently named and we registered their ages according to their ID cards or other legal certificates, which show they all are over the minimum age for the Olympics."