North Korea will not be able to send gymnastics teams to the 2012 London Olympics after international officials rejected the federation's appeal of a ban imposed because a gymnast falsified her age.

The International Gymnastics Federation said its appeal tribunal ruled Thursday from Lausanne, Switzerland, that North Korean explanations did not justify lifting a provisional 30-day suspension handed down last week because of Hong Su Jong's violation of age rules.

The ban prohibits North Korea from competing at any international competitions, including the world championships that begin Saturday in Rotterdam, Netherlands, and are the first step in qualifying for the London Games.

The top 24 teams at this weekend's event will advance to next year's world championships in Tokyo. North Korea still might be able to send individual gymnasts to London depending on whether more sanctions are imposed.

North Korea can make a final challenge at the Court of Arbitration for Sport.

The FIG imposed its ban after finding that Hong had entered the world championships using the third different birthdate of her career. She listed her birth year as 1989, but FIG documents show that she competed at the 2004 Athens Olympics and the 2006 world championships using a birth year of 1985. She won the silver medal on vault at the 2007 world championships listing 1986 as her birth year.

If Hong was born in 1989, she would have been ineligible to compete in Athens. Gymnasts must turn at least 16 in the calendar year of an Olympics to be eligible.

This is the second time North Korea has been punished for age falsification. The federation was banned from the 1993 world championships after the FIG discovered that Kim Gwang Suk, the 1991 gold medallist on uneven bars, was listed as 15 for three years in a row.

Age falsification has been a problem in gymnastics since the 1980s, when the minimum age was raised from 14 to 15 to help protect still-developing athletes from serious injuries. The minimum age has been 16 since 1997.

The FIG requires all gymnasts who represent their countries at most international meets to have a licence that proves their age for their entire career.