Qiu Zhanxuan, president of the Peking University Marxist Society, on December 17 in a photo published by the Jasic Workers Support Group.
Beijing CNN  — 

A high-profile Marxist student activist was bundled into a car by suspected plainclothes policemen on Wednesday on his way to celebrations for the birthday of former Chinese leader Mao Zedong.

Qiu Zhanxuan, head of the Marxist Society at China’s distinguished Peking University, is the latest in a series of socialist student leaders to vanish in recent months following their attempts to support Chinese workers in labor disputes.

It has raised fresh questions about the Communist Party’s Marxist credentials at a time when Chinese President Xi Jinping is working hard to paint his government as an ardent supporter of ordinary workers and citizens.

Qiu was on his way to attend a memorial on the 125th anniversary of Mao’s birthday early Wednesday when up to eight people in plain clothes grabbed his arms and legs and bundled him into a car, according to a fellow student who witnessed the incident.

The student, who asked to remain anonymous for fear of official reprisal, said he heard Qiu yelling, “I didn’t break the law, why do you want to take me away? What are you doing?”

According to the witness, the men who took Qiu away identified themselves as officers from the Ministry of Public Security. CNN has reached out to the Ministry of Public Security for comment.

“What’s wrong with remembering Chairman Mao? Which law does it break? How can they kidnap a Peking University student in public?” the student told CNN.

Before his disappearance, Qiu had been vocal in his support of Chinese workers and had called for people to celebrate the anniversary of Mao’s birth.

Peking University in Beijing, seen in the snow.

Student activists detained

At least 10 young Chinese labor activists have been detained in major cities across China since August, at times brutally. One Peking University student told CNN in November that even distributing leaflets could get people in trouble.

“The whole of Peking University is like under the white terror now,” he said.

It began following a labor dispute in June in southern China where workers at Shenzhen’s Jasic Technology called to set up a trade union.

The government declined their request but staff continued to petition. In July, dozens of workers were allegedly detained by police, with some claiming they were beaten by security guards.

In late July, a group of left-wing students, proclaiming themselves Maoists, traveled from around the country to join in the protests, drawing national attention.

One Peking University graduate, Yue Xin, published an open letter calling for students at universities across China to support the workers and sign a petition.

As public interest grew around the protests, the government quickly cracked down. Over the following months a number of students, including Yue, were abducted by groups of unidentified men.

In November, Peking University claimed it had uncovered and eliminated an “illegal organization” inside the school’s Marxist Society, saying the group’s goal had been to subvert state power.

It comes as President Xi continues to talk up the Communist Party’s Marxist credentials. In a major speech in December, he said China must uphold Marxism as its “guiding ideology” heading into the future.