Over two billion people or almost one third of the world’s population watched the opening ceremony of the 2008 Beijing Olympic Games, global market research company Nielsen said on Thursday.

The Nielsen Company said in a statement that it collected data from 38 key markets around the world, including host nation China, the United States, Brazil, South Africa, Italy and Australia.

Viewing level varied across regions and markets, impacted by factors such as time zone and broadcast time differences, the company said.

Comparing regions, the highest audience reach was in the Asia- Pacific, where more than five in 10 people watched the opening ceremony, followed by Europe, where 30 percent of the population watched, and North America, at 24 percent.

Looking at individual markets, the percentage of people tuning into the opening ceremony varied widely, the company said.

In China, 90 per cent of families tuned into the four-hour extravaganza on August 8, according to Nielsen's sister company AGB Nielsen Media Research in a separate news release.

The live broadcast set a new audience record in China for a single programme, according to AGB.

The percentage of people tuning into the opening ceremony elsewhere varied widely - from 44 per cent in South Korea and 43 per cent in Greece to only 8 per cent in Indonesia and 11 per cent in Argentina, The Nielsen Company said.

Viewing levels in the United States was impressive, the company said, estimating that 65 million there tuned into the broadcast.

The opening ceremony featured 29 sets of fireworks displays, as well as singers and dancers and special effects. An image of the Great Wall was displayed and thousands of panels moving up and down created the Chinese character for "harmony."

The show was widely perceived as being spectacular, but controversy broke out later after a Chinese agency revealed that the little girl who in theory sang the Hymn to the Motherland during the ceremony, barely mimed. The voice that charmed the world belonged to a different girl who was not put on stage because she was not considered pretty enough.

The series of revelations about manipulations at the opening ceremony started a few days ago, when it became known that only one of the 29 fireworks footsteps seen on television during the show had actually happened on the opening day of the Games.

The other 28 were made and filmed around Beijing on previous days, when the sky was clearer than on the opening night in which former gymnast Li Ning made his unforgettable "flight" around the inner upper ring at the National Stadium to light the Olympic flame.