Chinese police have detained a lawyer who sought to visit a prominent activist taken into custody this week, a Beijing-based dissident and overseas rights groups said on Friday.

Liu Weiguo was taken away in the capital while trying to see his client Xu Zhiyong, a professor who had urged the release of activists seeking asset disclosure by government officials.

"Since the afternoon the lawyer Liu Weiguo has had his personal freedom restricted," Beijing-based dissident Hu Jia said on Twitter late Thursday.

Liu was later told he did "not meet the qualifications to act as a defence lawyer", Hu tweeted on Friday.

Xu was detained on Tuesday for "gathering a crowd to disrupt public order", the US-based group Human Rights in China said.

Police have also held several Xu supporters who tried to leave money for him at the detention centre, the US-based China Human Rights Defenders said.

Altogether 25 activists, lawyers and other people have been detained since February for criticising official corruption and "promoting other politically 'sensitive' goals", CHRD added.

The arrests come as China's new leaders who took office in March have vowed to crack down on corruption within the ruling Communist party.

Scandals of government officials living lavishly -- with luxury watches, multiple mistresses or fancy cars for their children -- are frequently reported in the domestic press.

President Xi Jinping has warned graft could destroy the party and that offenders would receive no leniency.

But truly rooting out corruption would require taking on powerful vested interests, and analysts remain doubtful how far the anti-corruption campaign will reach.

Xi's extended family was reported by the Bloomberg news agency last year to have assets worth $376 million.

...,/.,