Ai Weiwei's wife questioned

As China's most famous artist and government critic has become more outspoken again in recent weeks, it seems the government is once again closing in.

On Tuesday, Ai and his friends reported that police came to his studio in the afternoon and led his wife, Lu Qing, away for questioning. Ai was away from the studio when the police arrived, and Lu was questioned for about two hours, reportedly over the same questions that have been asked before.

Ai, who was held without charges in secret detention for three months this spring during the Chinese government's crackdown on all dissent, was silent for several months following his release. Since he paid more than half of his $2.4 million tax bill -- which he denies owing -- the artist has grown more vocal and critical, granting multiple interview requests and returning to social media platforms.

Last week, he said his staff were questioned about a potential porn investigation related to his series of nude photographs. In response, groups of Ai's supporters posted online pictures of themselves and others in the buff, saying they wanted to educate the Chinese government that nudity doesn't equal pornography.