A former employee of the UK's consulate in Hong Kong has filed an official complaint about the broadcast by China's state-run CGTN of a confession he says he was forced to make.
Simon Cheng, a Hong Kong citizen who worked for the UK government for almost two years, was detained for 15 days on a trip to mainland China in August.
Mr Cheng says he was forced to "confess" to soliciting prostitution.
He has complained to the UK broadcasting regulator, Ofcom.
CGTN aired the confession in the UK as evidence of his alleged guilt.
The channel is the international arm of China Central Television (CCTV) and airs on UK platforms including Sky.
Mr Cheng denies China's accusation that he was soliciting prostitutes and says police had in fact questioned him about the UK's role in the Hong Kong pro-democracy protests.
Mr Cheng says the confession was extracted after he was tortured at a secret location in solitary confinement.
The segment was broadcast on 21 November. A newsreader told viewers he had "acknowledged his violation of the law".
Mr Cheng also told the BBC that he was accused by the Chinese of inciting political unrest in the city.
What's in the complaint?
Mr Cheng, whose current whereabouts is being kept secret, accused the state broadcaster of breaching various sections of Ofcom's rules in relation to privacy, crime and disorder, and impartiality among others.
Section seven of the code states "broadcasters must avoid unjust or unfair treatment of individuals or organisations in programmes".
The next section says "people in a state of distress should not be put under pressure to take part in a programme or provide interviews, unless it is warranted".
"I was under extreme distress and did not voluntarily make the recording," Mr Cheng says in the complaint.
"I was not asked in any way about this news production or broadcast. It was made by police and released by CGTN to exert pressure on me, without any prior contact with me at all."
Ofcom told the BBC: "We have received a complaint about a programme broadcast on CGTN which we are assessing as a priority."
Have there been other cases?
In September, the media regulator said it was investigating whether CGTN broke impartiality rules in its coverage of the Hong Kong demonstrations.
In May, it launched an investigation into a "confession" aired by CGTN of a British investigator.
Press TV, the Iranian state broadcaster's English-language outlet, was fined £100,000 ($129,000) in 2011 for airing an interview with Maziar Bahari, an imprisoned Newsweek journalist, which had been conducted under coercion.
The station had its UK license revoked in 2012 for breaching several broadcasting licence rules over editorial control of the channel.