Professor Lu Yong causes a disturbance on the plane. [Still image from China Central Television]

CHENGDU - A guest professor of a Chinese university has been sacked for causing disturbance on a plane bound for the United States, according to a statement from the university.

Lu Yong, a guest professor with the Southwestern University of Finance and Economics (SUFE), demanded a seat upgrade prior to his United Airlines flight from Shanghai to New York Sunday afternoon.

After his demand was rejected, Lu sat in the first class seat of another passenger, arguing with crew members as they tried to move him.

He then attacked three police officers who arrived after being called by the pilot. One officer suffered bruises on his chest after being pushed and kicked by Lu and the other two suffered from bites, according to a health report released Tuesday.

Lu is currently in custody for disrupting public services. He had been seen using a Chinese ID card.

The issue was widely discussed on the internet, with many speculating on Lu's identity.

On Tuesday, SUFE posted a statement on its official website, confirming Lu was a guest professor at the university.

"Lu is an associate professor with Pennsylvania State University," it said. "SUFE invited him to be a guest professor this past August...according to the contract, he can work and do research at our university for four months per year."

"It is our belief that professors should be morally respectable so as to teach their students," it said.