China is rushing to install sit-down loos for its 500,000 foreign Olympics visitors, after complaints that venues had only Asian-style squat toilets.
Demand for sit-down toilets is growing, said Mr Yao
A lack of Western-style facilities was a common complaint after some 30 test events at Games venues, officials said.
"A lot of parties have raised the question of toilets... We have told the venues to improve on this," said Yao Hui, deputy head of venue management.
He said bathroom renovations were already under way at three key venues.
"Most of the Chinese people are used to the squat toilet, but nowadays more and more people demand sit-down toilets," said Mr Yao.
"However, it will take some time for this transition."
The "Water Cube" venue lacked sit-down toilets
He said that the proportion of squat toilets to sit-down facilities would vary depending on the nature of each venue.
But he said most of the lavatories at the 91,000-seat National Stadium - known as the Bird's Nest, the Water Cube and the National Indoor Stadium "should be" sit-down style.
Beijing is said to be spending at least US$40bn on 37 venues for sporting events at the August Olympics, 31 of which are in Beijing.