Sports authorities have sometimes been accused of altering players' ages to show them as being younger, mainly to qualify them for youth tournaments.

Those false ages stay with athletes and can result in embarrassment and regulatory sanctions when athletes move on to greater success.

The practice, known as 'age shaving', is considered widespread in sports such as basketball and football.

But the opposite is suspected in women's gymnastics competition at the Beijing Olympics where China's women's gold medal team have been accused of amending birth records to appear older.

The reason: Female gymnasts are required to be at least 16 during an Olympic year to be eligible for competition.

The International Gymnastics Federation eventually cleared the Chinese team, but it continues to investigate the ages of Chinese gymnasts who competed in the 2000 Sydney Olympics.

While not limited to China, the problem of falsifying ages is considered particularly acute here owing to the massive pressure on coaches and officials to produce victories and the apparent ease with which false documents can be obtained.

Greater transparency and new technology are helping authorities to crack down on this practice.

This season, the China basketball federation has begun to check ages given on players' identification cards against a national police computer database, prompting a spate of confessions, according to the Oriental Sports Daily newspaper.

In all, 22 players gave birth dates when registering for this year's season that were different from ones given last year, the paper said. Some players were found to be up to four years older than originally stated, it said.

Reports named two teams from the provinces of Liaoning and Jiangsu as the biggest offenders, with several players faking their ages.

A Jiangsu Nangang club spokesman blamed the problem on provincial sports schools that first recruited the players.

'This year, we're following the request to provide the true ages of our players as shown on their ID cards,' said the spokesman, who declined to be named.

As some of the players named were on the national youth team's roster, the revelations could threaten international results going back six years, according to the popular Sina Sports Website.

ASSOCIATED PRESS