GANZHOU, China — China’s government on Tuesday rejected a U.S. State Department call to release three activists detained while investigating a factory that produced shoes for Ivanka Trump and other brands. It sought instead to enforce a cone of silence around the men, according to a lawyer and the wife of one detainee who was interrogated for hours herself.

The U.S. State Department on Monday called on China to release the men, who were detained last week after working undercover in a Chinese factory to check into worker abuses.

“We urge China to release them immediately and otherwise afford them the judicial and fair trial protections to which they are entitled,” said Alicia Edwards, a State Department spokeswoman. She said the U.S. remains concerned about “the pattern of arrests and detentions” and noted that labor activists are instrumental in helping American companies understand conditions in their supply chains and holding Chinese manufacturers accountable under Chinese labor laws.

Deng Guilian, the wife of one of the detainees, Hua Haifeng, said that she had been interrogated twice by police in her hometown in central China’s Hubei province. The police pulled her in for four hours of questioning that lasted past midnight on Friday, and then called her for a further interrogation on Saturday.

“In a normal situation, as a woman at midnight squeezed in the middle of four men – moreover they’re policemen – it’s impossible not to be nervous,” she said. “I was terrified.”

White House spokesman Sean Spicer said the State Department has made the U.S. position “very clear” and will “continue to exert the proper diplomatic pressure.”

On whether the president or Ivanka Trump would comment directly, he said “it’s a State Department issue.”

Adrienne Watson, a spokeswoman for the Democratic National Committee, said in a statement that “Ivanka’s company should switch suppliers, and the Trumps should stop hypocritically telling corporations to ‘buy American and hire American’ while they continue to knowingly take advantage of workers’ abuses abroad.”