Staff at two "safari parks" a few hours from the capital Beijing offered to sell undercover investigators wine made from the crushed bones of tigers that died in captivity at the sanctuaries.

The wine, which it is claimed, helps to cure conditions including arthritis and rheumatism, is advertised openly and sold at the parks.

The revelations that the parks are breaking the law are embarrassing for the Chinese government which is trying to promote a positive image of the country in the run-up to the Beijing Olympics in August.