Amway has not been singled out in the campaign, and it has built an impressive brand here, operating gleaming showrooms in Beijing and elsewhere and sponsoring the Chinese Olympic team. Yet it has been dogged by accusations like those it has faced elsewhere.

Former Amway distributors have organized online to warn others of the company’s model. Amway’s name in Chinese, an li, has entered the vernacular to mean to “promote heavily” or to “be brainwashed.”

Amway and others faced skepticism from the authorities nearly from the moment they entered the market in the early 1990s. Multilevel marketing was officially denounced as an “economic cult,” and in 1998 the government banned all direct selling.

Only when negotiating entry into the World Trade Organization did China agree to American demands to allow the companies in. Direct selling has been legal since 2005, though with restrictions intended to discourage the endless recruiting of new distributors, a component of Amway’s model.

Enforcement of the laws, however, remains uneven. “It’s a gray area,” said Liu Kaixiang, a professor at Peking University’s School of Law who conducts research at the university’s industry-affiliated direct-selling research center. “The majority of these direct-selling companies are right on the edge. If they were to completely follow the law, there would be no market at all.”

The vagaries of Chinese regulations and an avaricious bureaucracy have already ensnared others, like Avon, once the top direct seller here. In 2014, it admitted to providing $8 million in cash and gifts like Gucci purses to Chinese officials.