Vendors of illegally copied films, music or other copyright products on-line will face up to three years in jail, China's law enforcement agencies announced Tuesday in a pledge to crack down on "rampant" piracy.

The sentencing policy was revealed at a press conference, when the Ministry of Public Security announced that police had arrested more than 4,000 people suspected of intellectural property rights (IPR) violations since a crackdown began in November.

Gao Feng, deputy director of the ministry's Economic Crime Investigation Department, said more than 2,000 cases of piracy -- involving more than 2.3 billion yuan (347.5 million U.S. dollars) -- had been dealt with during the crackdown.

"The astonishing results, on the one hand, reflect the achievements of the police during the campaign, but they also underline the fact that IPR infringements are still rampant," said Gao.

Describing piracy as "an international economic drug," Gao said, "It stimulates the illegal desire of violators and suppresses people's innovative capacities."

The crackdown would continue until March, said Gao, calling on all law enforcement agencies to cooperate in the fight against cross-border piracy.

A circular jointly published by the Supreme People's Court, the Supreme People's Procuratorate, and the Ministry of Public Security Tuesday, states that anyone who earns more than 50,000 yuan (7,553 U.S. dollars) from on-line piracy faces the maximum three-year prison term.

Xiong Xuanguo, vice president of the Supreme People's Court, said at the press conference that the circular made the fight against on-line piracy more "maneuverable."

"As on-line information spreads fast and extensively, the judicial system and the police in some regions have long held varied views on how to define on-line piracy and what kind of penalties should be given," he said.

"This circular gives a clear answer."

The circular defines on-line piracy as the dissemination of a written work, music, motion picture, television program or other visual work, computer software or other works through the Internet for the purpose of making a profit and without permission of the copyright owner.

It also sets other sentencing criteria for "serious" on-line piracy, including:

-- The number of unauthorized works involved exceeds 500;

-- Related works have more than 50,000 page views;

-- Using a membership system with more than 1,000 registered members to disseminate other people's works.

In 2004, the Supreme People's Court and the Supreme People's Procuratorate made clear in an interpretation that on-line piracy should be seen as copyright infringement, but it failed to specify the threshold for such offences.