By Chris Hogg
BBC, Hong Kong
Hong Kong authorities are investigating after TV programmes beamed into China from the territory by satellite were allegedly hacked into at the weekend.
The Falun Gong movement is illegal in China
Content promoting the spiritual group Falun Gong, banned on the mainland, appeared on the satellite feed and was broadcast on two Chinese TV stations.
A Falun Gong spokesman in Hong Kong said she did not know if any of the group's followers were involved.
The group was branded an evil cult in China after an incident five years ago.
Ten thousand of its members besieged the leadership compound in Beijing demanding official recognition of their faith.
The movement, which combines Taoism, Buddhism and traditional Chinese breathing exercises, remains legal in Hong Kong, though, where freedom of religion is guaranteed.
On Saturday evening, television programmes promoting Falun Gong appeared on the feed beamed into China from a satellite owned by the Hong Kong company AsiaSat.
The operator says it does not know where the signal came from.
In its words, its satellite was attacked.
The company was forced to halt transmission for more than four hours, disrupting programming on two TV channels on the mainland.
Hong Kong's Telecommunications Authority has confirmed it is working with AsiaSat to try to track down the source of the signals.
A spokesman for Falun Gong in Hong Kong said she had checked message boards and other communications channels within the group and no-one was claiming responsibility.