BEIJING — China has effectively expelled a reporter working for The Wall Street Journal after he wrote an article about an investigation in Australia involving a cousin of China’s top leader, Xi Jinping, in the latest sign of a government clampdown on media freedom.

The Chinese authorities declined to renew the press credentials of Chun Han Wong, a reporter in Beijing for The Journal, a spokesman from Dow Jones, the parent company of the newspaper, said in an emailed statement on Friday.

“We continue to look into the matter,” the spokesman said.

In a statement, China’s Foreign Ministry said it handled matters involving foreign journalists in accordance with the law. But it added: “We are resolutely opposed to an individual foreign journalist maliciously smearing and attacking China. As for such journalists, we do not welcome them.”

The Journal’s article, co-written by Mr. Wong and published in July, said activities by Ming Chai, a cousin of Mr. Xi’s, were being scrutinized by law enforcement and intelligence officials in Australia.