The wife of an imprisoned human rights lawyer has been placed under house arrest and threatened with death after attempting a march from Beijing to Tianjin in defense of her husband.

China Aid reports that Li Wenzu organized a march from Beijing to Tianjin, a 71-mile trek, in search of her husband, Wang Quanzhang, who disappeared more than 1,000 days ago. At the time, he was seized as part of a nationwide crackdown on human rights lawyers. However, his current location is unknown, and he has not been allowed contact with his legal representation and loved ones for the entire duration of his imprisonment.

Li, who believes her husband is being held in Tianjin, was followed by reporters and friends as she set out from the Supreme People's Court in Beijing a week ago, holding their young child. A week into her trip, officers wearing street clothes seized Li and returned her to Beijing, where they have sequestered her in her home and not permitted her to leave, according to Reuters.

Wang Qiaoling, the wife of human rights lawyer Li Heping, who was also taken in the 2015 crackdown but has since been released, confirmed the arrest, telling Reuters, "Li Wenzu has been placed under house arrest, with state security blocking the door."

On Twitter, Li revealed she was "being controlled" by state security officers and threatened with death.

"On April 11, 2018, trapped at home by 40 or 50 people. A friend who came to visit was stopped and beaten. I can only climb out the window to shout," she wrote. "Wang Quanzhang has been disappeared for 1,006 days, and I've been under house arrest for two days. They even blocked our caretaker and our son from leaving the house, and said: if you come out, we'll kill you. It was only after I called the police that the guards allowed them to leave the house. But a gang of Aunties hurled insults at them, calling them traitors, and made them cry. If we-mother and son-are disappeared, are killed, we hope our friends everywhere will help us write this tragic episode into history.

Wang Quanzhang took on sensitive cases of complaints of police torture and defended practitioners of the banned Falun Gong spiritual movement, according to the Japan Times. He was one of more than 200 Chinese human rights lawyers and activists who were detained or questioned in the summer of 2015, the largest clampdown on the legal profession in recent history.

Wang has been charged with "subversion of state power" but authorities have blocked family-appointed lawyers from visiting him. The outlet notes that Wang's case is unusual because no trial date has even been announced. He is the last person in the so-called "709 crackdown" to remain in legal limbo.