The programmes praised the movement's founder Li Hongzhi

The unusual incident, seen as highly embarrassing given China's usually rigid control over broadcasting, saw two films being aired praising the Falun Gong and its US-based founder Li Hongzhi.

Since then there have been other examples of pro-Falun Gong material finding its way into state-controlled media, in some cases implicating local officials.

Xinhua said that in the Changchun incident, cable TV programmes suddenly stopped and were replaced by "an unclear and intermittent video broadcast about Falun Gong".

'Indignation'

Xinhua quoted local police officials as saying the interruption constituted "a well-organised, premeditated crime".

A Changchun-based emergency handling centre received more than 4,650 calls from the public on 5 March as people reported seeing the programmes.

Xinhua said callers also "expressed their strong indignation".

Earlier this month, a city prosecutor predicted that the organisers of the transmission would be charged with "using an evil cult to damage law enforcement", a crime which carries a maximum penalty of 15 years in prison.

The Falun Gong movement, which China says is trying to overthrow the Communist Party, was banned on mainland China three years ago.

Falun Gong says it is spiritual group that teaches exercise and meditation.

The pirate programmes went out to much of the network of 300,000 subscribers, giving a potential audience of around one million.