Chinese film director Zhang Yimou

A commercial for China's railways allegedly directed by Zhang Yimou that cost 18.5 million yuan ($2.9 million) triggered criticism online, the Beijing News reported Tuesday.

The audit authorities recently published the Railway Ministry's revenue and expenditure for 2011 and exposed that the ministry invested 18.5 million yuan in an advertising film.

Internet users found out that the 5-minute video gave directing credit to Zhang Yimou and said the film does not warrant the high cost and questioned the huge investment.

The film reviewed the achievements of China's railways over the past few decades and tells the story with captions. Internet users figured that each minute cost 3.7 million yuan.

Pang Liwei, an assistant to Zhang, said, "Director Zhang refused to sign his name on the film and the production company entrusted by the Railway Ministry agreed. Zhang did not get involved with any part of the shooting and only made suggestions during pre-production."

As to the high cost of the video, Pang said, "It's the pay a director of Zhang's level should get. We charge the same for other advertising films and we pay full taxes."