BEIJING - When Gao Yu was 15 minutes late for our interview we figured the outspoken former journalist was stuck in traffic. After a half hour we called her mobile phone and it went unanswered.

When an hour had passed and there was still no sign of her we genuinely began to worry.

Concern is a natural reaction here when a prominent activist jailed after the 1989 crackdown in Tiananmen Square appears to be missing.

Back then, Gao was detained for 14 months and in 1994 was sentenced to six years for writing about Communist Party politics. Internationally, she is regarded as a champion for press freedom. In China, that can be a liability.

In our case, Gao eventually appeared, apologizing and juggling a bouquet of flowers she picked up for a friend’s birthday. We asked if everyone defaults to the same assumption when she is running late.

“During sensitive times I am still followed and my phone is tapped,” she said. “The Chinese government is now the richest in the world but they spend money on this... it is such a huge waste.”

So late last month, when Gao Yu failed to show up at a conference then to answer the door at her home, a familiar yet uneasy feeling settled over those who know her. At first not even her son could explain her disappearance and now he is reportedly missing too.

This time the concern was warranted.

China’s government announced that Gao Yu has been criminally detained for obtaining and leaking Communist Party secrets to a foreign website. State broadcaster CCTV showed a woman identified as Gao dressed in prison garb being paraded down a hallway to a room. There, the video shows her face obscured by a digital blur and her voice is heard giving a confession.

“I think what I did touched on the law and endangered the interests of the nation. This was very wrong. I have sincerely learned my lesson and also wish to admit guilt.”

Authorities say they seized “substantial evidence”, according to the official news agency Xinhua. Their television report also showed police searching Gao’s home.

Gao’s arrest is only the latest in a string of detentions ahead of the 25th anniversary of the Tiananmen crackdown and it is difficult to understate the sensitivity here. Few moments in modern history have so sharply defined ‘the new China’ and fewer still are capable of stirring the sort of tension currently brewing in Beijing.

Authorities this week have detained intellectuals and activists including prominent rights lawyer, Pu Zhiqiang, in a bid to stifle any signs of dissent.

On the latest charges against Gao of leaking secrets, it is unclear which document and website are in question or where the case goes from here.

There is speculation it could be related to so-called “Document No. 9” which Gao wrote about last year. It apparently details the Communist Party’s vision of economic reforms and preventing any challenges to its rule.

According to the Associated Press, the document argues for curbing notions of democracy like freedom of the press and universal values that challenge the Party’s legitimacy.

“When it comes to freedom of speech,“ Gao Yu told me in our interview, “this is no different than Chairman Mao’s era.”

Human rights groups have condemned the trend of silencing critics here along with what appears to be a new tactic of public shaming through televised confessions. Sophie Richardson, China director for Human Rights Watch, told news outlets that the recent detentions “lay bare just how little the Chinese government’s attitudes towards human rights have changed since 1989.

During that recent interview with Gao Yu I asked her how the atmosphere in China these days compares with the mood leading up to the pro-democracy protests 25 years ago. She said the problems facing the country today are more severe and almost incomparable to those in the past.

“The cronies prevent reforms from happening to protect their own interests. I don't see the coming of political reform,” she said, “It is now the most corrupted time in history.”