BEIJING (AFP) - The Chinese police said on Thursday they have detained a suspect in connection with the alleged hacking of a Chinese cable television service after it broadcast censored Tiananmen crackdown pictures and messages condemning the ruling Communist Party.

Police in the eastern Chinese city of Wenzhou, where the suspected hacking took place on the evening of Aug 1, said a 40-year-old IT engineer surnamed Wang was detained at Beijing's international airport on Aug 16.

Further investigation is under way, Wenzhou police said on their verified social media account on Sina Weibo, a Chinese version of Twitter. No explanation was given for the delay in announcing the details of Wang's detainment.

At the time of the apparent hacking, viewers in Wenzhou had used social media to post images of television slogans referring to the Communist party as "bandits", and photographs of the bloody 1989 crackdown on pro-democracy protesters in Beijing.

Such images are almost never shown by media in China, where the Communist Party censors anti-government messages and references to incidents it deems sensitive such as the Tiananmen crackdown when the army killed hundreds - by some estimates more than 1,000 - protesters.

One photograph showed the channel displaying the iconic "Tank Man" photo from the 1989 crackdown, showing a lone man standing in front of a column of tanks.

Subscribers were also shown graphic images showing apparent human rights abuses in the country, such as a protester being squashed under a truck.

China's Communist Party does not tolerate organised dissent, and has regularly jailed members of any group which challenges its right to rule the country.