Coca-Cola will screen a film at the China Olympics focusing on hand-picked "environment champions", as part of the group's strategy to improve its image on sustainability.

The documentary, to be shown at 8:30pm on 13 August in Beijing, will feature seven local environmentalists chosen by Coca-Cola to take part in different legs of the recent, and highly controversial, Olympic Torch Relay around the world.

"The Olympic Games provide a great platform to demonstrate the Coca-Cola system's commitment to sustainability and help raise global awareness about the importance of environmental stewardship," said Muhtar Kent, president and CEO of the Coca-Cola Company.

Coca-Cola has been no stranger to criticism on environmental issues. In one of the most high-profile cases, it has repeatedly faced, and strongly denied, allegations over its use of water supplies in Kerala, India.

The soft drinks giant is running several environmental programme during the Olympics, including a presentation of Coca-Cola t-shirts made from a blend of cotton and recycled PET plastic bottles.

All of the group's vending machines at the Games contain a natural refrigerant that will not emit hydrofluorocarbons (HFCs), one of the worst greenhouse gases. The machines also contain new technology to improve energy efficiency by around a third, the firm claimed.

The Coca-Cola film will be screened at the Coca-Cola "Shuang Experience Center," within the Olympic Green complex of sports and media venues.