Chinese police detained a lawyer after he used social media to poke fun at President Xi Jinping over the naming of a close relative in the Panama Papers, the man’s attorney said Friday.

Ge Yongxi, a civil rights defense lawyer, had posted an edited image mocking Xi on the WeChat messaging service about 2:30 p.m. Thursday. Around midnight, plainclothes police officers came to his house in Guangzhou and took him away, according to Ge’s attorney, Chen Jinxue.

“The police said he had published a post about the nation’s leaders that had a great impact and asked him to delete the post,” Chen said.

The Panama Papers — data leaked from a Panamanian law firm that exposed offshore accounts held by prominent politicians and others — have become a source of embarrassment for China’s Communist Party despite the absence of direct evidence of wrongdoing. The party habitually clamps down hard on stories about the wealth of top leaders and their families, and has instructed local media not to cover stories about the data leak. Social media references to it have been deleted.

Ge’s post purported to show past and present Chinese communist leaders Deng Xiaoping, Jiang Zemin and Xi Jinping bare-chested and up to their waists in water.

The image was labeled “The Panama River.”

Deng says, “It is really deep!”

Jiang says, “So easy to get drowned.”

Xi says, “Don’t be scared, I have a brother-in-law.”

Xi’s brother-in-law, businessman Deng Jiagui, was among a handful of elite Chinese citizens with family ties to at least eight current or former top leaders who were named in reporting and documents about offshore holdings published this month by the International Consortium of Investigative Journalists.

The term “brother-in-law” briefly became the subject of jokes on Chinese social media after the Panama Papers were released — and before Chinese censors went to work. It was not clear whether Ge’s post had been circulated beyond his circle of immediate friends.

Police at the Yanbu detention center, under the Foshan police station in the southern province of Guangdong, declined to comment on the case.

This week, the State Department criticized Beijing’s “severe crackdown” on lawyers and law firms who cover cases that the Chinese government considers politically sensitive.

Ge has been active in civil rights cases since at least 2013, according to media reports. He defended Tang Jingling, a prominent rights lawyer who was sentenced to five years in jail in January for subversion. Ge was banned from leaving China while defending Tang.

He was detained in June while defending another lawyer and again taken for questioning in July over his involvement in the lawyers’ rights movement.