Authorities in the southern Chinese city of Guangzhou are continuing to hold a top human rights lawyer with no announcement of criminal charges against him, in spite of a vocal campaign for his release, activists said Thursday.

Yang Maodong, better known as Guo Feixiong, was criminally detained on Aug. 8 on charges of “incitement to disturb public order,” after being involved in anti-censorship and anti-corruption protests.

“The authorities have made one arrest after the other in recent months, and this is still going on,” said Beijing-based fellow activist and poet Wang Zang, who was among dozens of campaigners who signed a public petition calling for Guo’s release.

“This is human rights violation on a massive scale.”

Wang said those who signed the letter were angry at the ongoing crackdown on activists who have called since March on the highest-ranking ruling Chinese Communist Party leaders to reveal details of their assets, and those of their families.

“We wanted to protest this political oppression, but also to reiterate that Guo Feixong is innocent, and should be released immediately,” he said.

“None of us is safe, and any one of us could be next.”

Corruption activist

Guo was released from jail in September 2011 following a five-year jail term and has previously been subjected to extrajudicial detention and torture.

The rights lawyer, whose wife and two children were granted political asylum in the United States in 2009, rose to prominence during a 2005 campaign by the people of Guangdong’s Taishi village to recall their elected chief amid allegations of corruption.

He was sentenced to five years’ imprisonment in 2006 by a Guangdong court for “illegal business practices” after repeated beatings and detentions did little to deter his rights campaigns.

Detained civil rights activist Xu Zhiyong, who is being held at a Beijing detention center on public order charges after calling on China’s leaders to reveal their assets in March, had recently called on ordinary Chinese to take a stand to protect the rights of citizens.

President Xi Jinping has launched a nationwide clampdown on corruption, warning that the Communist Party must beat graft or lose power.

However, police continue to detain activists who call for greater transparency.

The overseas-based Chinese Human Rights Defenders (CHRD) said last week it has confirmed the criminal detentions or disappearances of 58 individuals in the ongoing crackdown on anti-corruption activists, half of whom have been formally arrested.

Authorities in Beijing are preparing to try anti-graft activists Yuan Dong, Zhang Baocheng and Ma Xinli for “unlawful assembly” after they held up banners in the street calling on officials to disclose their assets in late March.

Hubei activist Liu Jiacai, Shenzhen-based activist Yang Mingyu, known as Yang Lin, and Hunan-based activist Li Huaping, known by his online nickname Nuowei Senlin are also being held in detention centers for similar activities.

‘Gray economy’

China’s hidden household income—otherwise known as its “gray economy”—has topped 6.2 trillion yuan (U.S. $1 trillion) or about 12 percent of the world’s most populous nation’s economic output, a new report says, indicating a widening wealth gap fueled by corruption.

The state-backed China Reform Foundation report, which provided the 2011 figures, said most undeclared income in the Chinese economy is undocumented and is held in the hands of relatively few people, according toCaixin magazine this week.

The richest 10 percent of urban Chinese made an average income of 188,000 yuan (U.S. $31,000) in 2012, more than three times the officially reported income level.

According to the study, rich city-dwellers have an income around 21 times that of the poorest Chinese, compared with an officially reported factor of 8.6.

Widespread mismanagement of public funds, loose monetary policy and lax enforcement of regulations were to blame for the growth of China’s hidden economy, the report said.

It said state-sponsored monopolies, rampant public sector corruption, and a lack of effective public oversight had contributed to the problem.

Reported by Yang Fan for RFA’s Mandarin Service. Translated and written in English by Luisetta Mudie.