The production team built a wooden bridge, three workshops, and a steel and concrete set during filming at Bigu during May and June 2004, the administration said in its statement. Footpaths and a gravel access road were also built, destroying a 500-square-meter (5,382-square-foot) patch of azaleas and other flowers, it said.

More than one year later, in August 2005, the producers hired a local agency to restore the area, but for "various reasons" the work still had not been completed before media reports about the issue appeared in April, the bureau said.

The buildings have since been torn down and garbage cleaned up, but the area 2,000 kilometers (1,250 miles) southwest of Beijing may never fully recover, it said.

Chinese tourism authorities refer to the traditionally Tibetan region as "Shangri-La" after the mythical land made famous in James Hilton's 1933 book "Lost Horizon."

The case underscores China's weak environmental regulations and lax enforcement, a situation the bureau's statement acknowledged.

"Clearer regulations, standards, and management are needed to protect our national ecology," the bureau said.

"The Promise," a US$35 million (euro27 million) production, was praised for its stunning visuals and won a Golden Globe nomination for best foreign film. Scenes shot at Bigu pond accounted for a significant portion of the movie.

One of China's most famous directors, Chen is best known abroad for 1993's "Farewell My Concubine" starring Gong Li and Leslie Cheung.