The arrest in Hong Kong of a journalism professor has disturbed academics and journalists alike.
Authorities detained Allan Au, a lecturer and consultant at the Chinese University of Hong Kong (CUHK) journalism school, on April 11 for allegedly conspiring to publish seditious material.
Au, who was released without charge, is the third journalist connected to news website Stand News to be arrested.
"This arrest gives a disturbing message and signals a chilling effect to outspoken opinion writers as well as academics who commit themselves in public debate," said Eric Yan-ho Lai, a law and political expert.
"Dr. Au's research and teaching interests are censorship and self-censorship in the industry of journalism. His arrest is obviously, and sadly, an example of how the authorities censor and punish dissenting voices in the city," Yan-ho Lai told VOA.
The press office at Hong Kong's Security Bureau told VOA via email that it does not comment on individual cases.
The email, attributed to a spokesperson, said people and organizations "must abide by the laws," and that any law enforcement action be "based on evidence, strictly according to the law."
The email added that press freedom is protected under the city's laws and bill of rights but is "not absolute and can be restricted for reasons including protection of national security."
For two decades, Au, 54, worked as a producer for TVB News before switching to academia. He was a Knight Fellow at Stanford University in 2006 and earned a doctorate from CUHK, where he later worked as a lecturer with a focus on new media and censorship.
He also provided commentary for the Ming Pao newspaper and Stand News, and for his own blog. Often, that writing touched on sensitive issues such as the national security law.
Stand News ceased operations December 29 after police raided its newsroom as part of a sedition investigation.
The news website's top editors Chung Pui-kuen and Patrick Lam were charged under the colonial-era legislation. Both were denied bail.
Authorities did not specify what articles or content led to Au's arrest, but Yan-ho Lai said he believes it is "highly possible" it is connected to the Stand News case.
He said that two pro-Beijing newspapers highlighted articles by the academic that they said could be seditious.
Lokman Tsui, a former media professor at CUHK who is now in the Netherlands, said Au's arrest shows "a steady escalation of the repression and erosion of press freedom."
"It seems the authorities are now going after people with bylines and public intellectuals. The authorities are instilling a massive culture of fear and self-censorship," Tsui, a free speech and digital rights expert, told VOA.
"(Au is) a journalist and a journalism teacher with a conscience, with the courage to be critical," Tsui added.
Following the arrest, U.S. State Department spokesperson Ned Price said, "Hong Kong's position as a free, global financial center depends on the free flow of information and opinions."
"Journalism is not a crime," Price added in a tweet.
Media watchdog Reporters Without Borders (RSF) has said that Hong Kong authorities are determined to eradicate press freedom.
"The detention of a third journalist from Stand News … months after the media's forced shutdown shows the government's determination to put an end to press freedom in the territory," the group's East Asia bureau head, Cédric Alviani, said in a statement.
RSF has said that Hong Kong's use of legal action, including the National Security Law, to punish what it deems "crimes against the state" has made journalism more dangerous.
Any media outlet that take a pro-democracy stance is at risk of being targeted by authorities, according to Keith Richburg, a journalism professor at the University of Hong Kong.
"I think it's inevitable you're going to see a lot more reporting done about Hong Kong from outside of Hong Kong, just because the restrictions are too great and the risks are too great," Richburg told VOA in January after Stand News shuttered.
The space for media freedom has been shrinking, with pro-democracy papers including the iconic Apple Daily being forced to close, and changes at public broadcaster Radio Television Hong Kong (RTHK) leading critics to question its editorial independence.
Au was a radio host at RTHK for 11 years until an overhaul at the broadcaster last year resulted in several contracts not being renewed.
Apple Daily closed in June 2021 after authorities charged senior executives under the security law and froze the company's financial assets. Jimmy Lai, the company's founder who has been in jail since the end of 2020, could face life in prison if convicted.
Lai and his lawyers made an appeal early in April for the United Nations to investigate his imprisonment as "legal harassment."
A statement from Lai's counsel said the media mogul faces life in prison "simply for speaking out, and for seeking to defend freedom of the press, democracy and the rule of law in Hong Kong." Lai's lawyers are awaiting a response.