A Chinese Olympic official has acknowledged that organizers of last week's opening ceremony faked a portrayal of ethnic minority children, in the latest controversy involving the lavish celebrations.
Olympic organizers had previously said the children were from China's 56 officially recognized ethnic groups.
But Beijing Olympic organizing committee deputy director Wang Wei on Friday acknowledged that was not true. Wang said it was normal for performers to portray different ethnicities.
His statement was in response to questions from foreign journalists, who were told by an official (Yuan Zhifeng) with a children's art troupe that the performers all came from her all-Han troupe.
Dozens of children wearing ethnic costumes walked across the Bird's Nest Olympic stadium last Friday holding a huge Chinese flag, which they passed on to marching People's Liberation Army soldiers.
Such scenes of national unity are common during state-sponsored celebrations in China.
But critics have accused China of using the Olympic Games to obscure tensions between the Chinese government and ethnic minorities.
Chinese authorities have cracked down on political dissidents and tightened security measures in Tibetan and Uighur areas in the run up to the Games.
Friday's revelation follows controversy about a lip-synching child singer and digitally-enhanced fireworks in Chinese television coverage of the opening ceremony.
Also Friday, Human Rights Watch called on the International Olympic Committee to investigate allegations of media abuse by Chinese authorities.
The IOC expressed concern this week about the treatment of a British television journalist who was briefly detained while filming a protest by pro-Tibet activists.
Students for a Free Tibet says 36 members and supporters have been detained by Chinese police since the beginning of the Games. Most have been quickly deported.
China has created officially-designated protest parks for the holding of demonstrations. But rights groups say those who have applied to protest legally have been harassed or detained.