WASHINGTON -- For Chinese artist and activist Ai Weiwei, the line between his public and his private life is thin. This is made abundantly clear in a 90-minute documentary, Ai Weiwei: Never Sorry.

When filmmaker Alison Klayman graduated from Brown University in 2006, she knew she wanted to be a journalist or a foreign correspondent. Her only experience, however, was an internship at National Public Radio’s All Things Considered and some other radio work. So she went to China, bought a camera and began filming Ai at his home, a walled courtyard with 40 cats and dogs, and at his studio, where fellow artists help him create his masterpieces.

The result is a documentary that shows clearly why Ai has become such a thorn for the Chinese government.

“Who knew that a movie about an artist was going to have so many lawyers in it?” said Klayman. “And activists and filmmakers.”

Ai has become an international superstar known for his art, but it is his activism that fuels his fame. He was invited by the Chinese government to help design the 2008 Beijing Olympics Bird’s Nest Stadium. But then he rejected doing any publicity on China’s behalf shortly before the Games.

He is known for his provocative performance art, including dropping 1,000-year-old clay pots to smash into pieces on the floor. But it is the photographs showing him giving the middle-finger salute to Tiananmen Square that directly challenge China’s government.

His preoccupation with the 2008 Sichuan earthquake, which killed 70,000 people, is another constant source of tension with the government. Struck by online videos of the dead, particularly the thousands of children who died in collapsed schools, he started a “citizen’s investigation” to get the names of all the children whose dust-covered knapsacks he’d seen discarded in the rubble of the substandard concrete buildings. He sought out volunteers on Twitter, who descended on the stricken area and came away with lists of the dead, including their ages, birthdates and schools. One year later, he published all 5,121 names on his blog, and the lists, on paper, are a regular backdrop to scenes shot in his studio.

He revisited the theme again in a 2009 exhibit in Munich called Remembering, where he built a wall of knapsacks whose different colors spelled out a Chinese phrase sent to him by the mother of one of the victims — “She lived happily on this Earth for 7 years.” A year later, he asked people to record themselves reading a name and send the file to him on Twitter. He published the audios again on the anniversary.

After the 2009 list was made public, the government shut down his blog.

He has turned to Twitter as his major means of communications. “I’m mostly interested in communication. I couldn’t think of a world without good communication,” Ai says at one point in the documentary. “In the past two years I did about 10 to 15 documentaries. I put all those on Internet so that young people can see ‘this clown, and what he’s doing.’”

In 2011, Ai was arrested and disappeared for 81 days. Returning to his compound, he said he couldn’t speak of what had happened under the terms of his probation. This didn’t stop him from returning to Twitter shortly after. The Chinese government levied a fine of $1.85 million on him for unpaid tax and fines. After he posted this on Twitter, citizens drove to his compound and donated yuan.

Klayman sees Ai as more cautious now, partly because of his young son, Ai Lao, born to a girlfriend outside of his marriage, a circumstance he talks about openly, if somewhat embarrassedly, in the film. He doesn’t want the son to end up as a leverage point between him and Chinese government. One question weighs over Ai, who lived for 16 years in the New York, one of the first Chinese allowed to study abroad when China began its opening to the West: Could he be forced into exile? Recently Chen Guangchen, a blind civil rights lawyer who escaped house arrest by fleeing to the U.S. Embassy in Beijing and then, ultimately, by flying with his family for a fellowship at New York University.

Klayman says she thinks that would not be Ai’s choice. “I don’t think he wants to be a citizen of anywhere but China, to be honest,” she said. “I do still think that that’s true, but what options the authorities present to him may result in some other choice having to be made. But I think . . . if he had his choice, absolutely he wants to stay in China to do the work there, to be relevant there.”