A vice chairman of a top political body has come under investigation for "disciplinary violations", state media reported on Saturday, as authorities pursue a high-profile crackdown on official corruption.

Su Rong "is being probed for suspected disciplinary violations", the official news agency Xinhua said, citing the ruling Communist Party's anti-graft watchdog, the Central Commission for Discipline Inspection.

Such violations typically refer to graft, although details about Su's circumstances were not provided.

Su is one of 23 vice chairs of the Chinese People's Political Consultative Conference (CPPCC), a debating chamber that is part of the Communist Party-controlled governmental structure.

He took the post during a power handover in March 2013 which saw President Xi Jinping and many other new government leaders take office.

The CPPCC plays a largely symbolic role, with members meeting once a year to discuss social and economic policies, among them wealthy business leaders and members of powerful political families.

Communist Party leaders who took power in late 2012 have repeatedly pledged to crack down on widespread official corruption -- a source of deep public discontent -- vowing to go after both high-ranking "tigers" and low-level "flies".

A wide swathe of officials have since come under investigation, but analysts say that without systematic changes the effort is unlikely to root out corruption fundamentally.

Chinese police arrest prominent rights lawyer
Beijing (AFP) June 13, 2014 - Police in China on Friday arrested one of the country's most celebrated human rights lawyers, as leaders of the ruling Communist Party renew their push to punish government critics.

Pu Zhiqiang, a prominent rights campaigner who has represented dissident artist Ai Weiwei, was arrested on suspicion of "creating disturbances and illegally obtaining personal information", according to a posting by the Beijing Public Security Bureau on its verified microblog.

The police added that a further investigation into Pu's "other alleged crimes" was under way.

Pu's lawyer, Si Weijiang, maintained that political reasons were behind the arrest.

"He's innocent. He hasn't committed these crimes," Si told AFP by phone Friday night.

He said that authorities had likely been incensed by critical statements Pu had made on his Sina Weibo microblogging account, which has repeatedly been shut down.

Chinese authorities routinely round up outspoken critics of the Communist Party in the weeks before key events, and Pu was among several people detained last month after attending a private seminar commemorating the 25th anniversary of the Tiananmen Square crackdown.

More than 40 journalists, lawyers, scholars and activists were held under various forms of detention ahead of the June 4th anniversary, Amnesty International said, in a larger clampdown than in previous years.

Meanwhile a wider crackdown on dissent has been under way ever since Chinese President Xi Jinping took office last year.

The campaign has targeted even moderate critics of the Communist Party, alarming many Chinese activists and lawyers and drawing condemnation from the US, EU and international rights groups.

Prominent legal activist Xu Zhiyong was sentenced to four years in prison in January for backing demonstrations in which a handful of protesters held up banners calling for government officials to disclose their assets.

Concerns about Pu's condition began to mount days after the Tiananmen anniversary, when he remained in detention even as other activists and lawyers were released.

- Daily interrogations -

On Monday, police denied bail to Pu, friends said.

Courts in China are controlled by the ruling Communist Party, and arrests typically lead to conviction.

Zhang Sizhi, a longtime rights lawyer, wrote in an online posting Wednesday that he was able to meet with Pu this week and that the detained lawyer has been subjected to daily interrogations lasting as long as 10 hours.

Several associates of Pu were also detained ahead of the Tiananmen anniversary including journalist Wu Wei and Xin Jian, a Chinese staff member of the Japanese financial newspaper Nikkei who recently interviewed the lawyer. Wu and Xin were released last week, according to campaign groups.

Amnesty International condemned Pu's arrest Friday night and called on authorities to release him.

"These are trumped up charges against Pu Zhiqiang," said William Nee, China researcher for Amnesty. "The Chinese authorities must end the witch-hunt against those championing the rights of others and immediately release Pu."

"The past month has seen a widespread campaign of repression with the authorities going further than in previous years, both in terms of who has been targeted and the harsh measures being used," he added.

As news of Pu's arrest circulated late Friday, Ai -- the dissident artist who repeatedly clashed with authorities and has been denied a passport -- made note of the arrest on his Instagram photo-sharing account.

He posted a photo of Pu, a news story about the arrest -- and a Chinese-language expletive in the comments section below.