“Zhou Shifeng and the others are suspected of other serious crimes, and the case is still under investigation,” it said, citing the police. The reports did not describe the specific crimes they are accused of.

The reports came after many of the suspects had disappeared into police custody on Thursday and Friday. Over the same time, nearly 60 other lawyers and activists had also been detained or went out of contact, a sign that they may have been detained, said the Chinese Human Rights Defenders, a group in close contact with many activists. Some of the detainees were released after questioning by the police.

Experts and rights advocates said the blast of state news media reports about Mr. Zhou and his colleagues appeared to be an aggressive attempt to discredit all rights lawyers and activists as greedy schemers who menace social order.

“It reflects the Xi Jinping approach — bold and neo-totalitarian — but then it also reflects the strength of the movement,” said Eva Pils, a law scholar at Kings College London who studies China’s broad movement of rights defense lawyers. “They see a need to delegitimize it, to officially declare the human rights lawyers enemies of the state.”

Citing a police investigation, the report said that Mr. Zhou had overseen a series of “sensitive cases,” in which lawyers mobilized aggrieved citizens, fanned publicity over the Internet and used aggressive courtroom tactics. The lawyers wanted to enrich themselves and to undermine the party, said the report, which also cited purported confessions from one of the lawyers as well as two activists, including one employed by Mr. Zhou’s law firm.