The network said Monday it had used a hidden camera to film the beatings and claimed this was the first time such pictures had been taken of police interrogation in China.

CTV's Beijing reporter, Holly Doan, said the filming was in the second floor of a building in a Shanghai alley.

The film opens with a shot, from the street, of the back view of a man handcuffed to the bars of a window.

A similar shot of another man in a similar position is also shown.

CTV executives in Toronto were unable to provide details of how the film was shot -- apart from saying it was with a hidden camera -- or what type of microphone was used to capture the sounds of a man having his face slapped and his interrogator shouting questions at him.

Most of the footage is of the back of one man, leaning forward with his hands cuffed to the bars of awindow. It appeared that both the camera and the microphone were at street level just outside the building where the prisoners were being interrogated.

At first, he is apparently punched in the stomach several times, later he is clearly having his face slapped. Doan said he was unshackled after a 15-minute briefing. Talking over the sound, Doan said the interrogator was shouting "will you talk, or not."

Doan said the prisoners were "shackled day and night."

CTV said the filmed evidence would likely be an embarrassment for Prime Minister Jean Chretien who has carried out a policy of rapprochement with China since first coming to power in 1993.