BEIJING (Reuters) - An award-winning Tibetan film director has been detained and suffered serious injury while in police custody, a Chinese film directors' guild said on Wednesday, though police said he was only lightly injured being taken away from a luggage dispute.

Pema Tseden, a renowned Tibetan filmmaker best known for the films "Tharlo" and "Old Dog", was detained at an airport in western China on Saturday, the Film Directors' Guild of China said in a statement posted to its official microblog account.

He was badly hurt in the course of his detention, the statement added, and was then taken to hospital in the western Chinese city of Xining on Monday.

Pema Tseden could not be reached for comment.

Xining police did not respond to repeated calls, but in a statement on its official microblog police said he had got into a dispute with security guards after trying to return to the luggage reclaim hall having forgotten an item.

He was then detained, but as he refused to cooperate he ended up with bruises from the handcuffs, police said.

On Monday morning, he was taken to hospital after feeling dizzy and complaining of tightness in his chest, and was briefly hospitalized for high blood pressure and blood sugar levels, police added.

His rights were protected at all times, police said.

Pema Tseden is China's first director to make films entirely in the Tibetan language. His work has won many prizes at home and are not critical of Beijing's rule over Tibet.

Rights groups say China, which took control of Tibet in 1950, has tried to stamp out religious freedom and culture in the Himalayan region. China rejects the criticism, saying its rule has ended serfdom and brought development.

People with knowledge of the case told Reuters they believed police had not recognized the director and detained him after the dispute.

"(We) call on the relevant authorities to quickly respond to the association's concern, and make public the whole story of this incident, including the reason for police taking forceful measures," the guild said in a statement.

Abuses by Chinese police departments, which are largely unregulated, are common in China, but this case generated unusual fervor on social media networks because of the director's fame. Tibetans on Chinese social media networks called for calm.

In May, there was a major public outcry after an environmentalist who had graduated from a prestigious Beijing university died in police custody.

(Reporting by Megha Rajagopalan; Additional reporting by Ben Blanchard; Editing by Nick Macfie)