He wanted to go to church _ the only chance for a brief escape from house arrest. But Zheng Enchong knew the police by the elevator might stop him, so he decided to try something new.

He dialed China's equivalent of 911, hoping other police officers might help him get out of the building. Instead, he was ignored.

"I wanted to see what would happen," the activist lawyer explained in a rare interview at his home. "You can say I still believe in the law."

That belief has been sorely tested. In the years since he started looking into possible land-related corruption at Shanghai's highest levels, the balding, bookish 57-year-old has been beaten, imprisoned, refused a passport, stripped of his right to practice, and now confined indefinitely to his 14th floor apartment in a blue-collar district of Shanghai.

Zheng is among a small number of outspoken lawyers in China who are determined to push forward a legal system that has been pieced together from almost nothing over the last 30 years.

Some lawyers choose to focus on human rights. Zheng works on property rights, a less glamorous but more pressing issue for the many Chinese uprooted by breakneck urban development. But he has found that targeting powerful interests risks police harassment, or worse.

"This is not a man who was taking part in ... any allegedly subversive activity," said Jerome Cohen, a professor at New York University and an expert in the Chinese legal system. "He had a day-in, day-out job of helping people with their real estate problems. It got turned into a human rights problem. It's a personal tragedy he's been singled out like this."

Zheng's phones are often disconnected. He says hospital officials could not reach him last October to tell him his 95-year-old mother was dying. When he managed to visit the hospital to see her body, four police cars followed.

He and his wife, Jiang Meili, wage a small daily war against the harassment. "Help, police are beating people!" Jiang yelled from a window one day after another scuffle with the police camped in the hallway. Neighbors didn't respond.

On a recent day, when the building guard saw an Associated Press reporter produce a camera, a furious argument erupted.

"Are you Chinese?" a guard shouted at Zheng and Jiang. "What are you telling the foreigner? You traitors! They come here to take photos of you, and in our eyes you look like dogs."

"Real Chinese speak the truth!" Zheng and his wife shouted, the petite Jiang shaking a tiny finger in front of the guard's nose.

Zheng says his months of house arrest intensified in February when he suffered several police beatings. He now fears it won't end until the Beijing Olympics are over on Aug. 24, if at all. With the Olympics coming, he said, "I think they're just looking for an excuse to give me trouble."

A spokesman for Shanghai's police, or Public Security Bureau, denied police were monitoring Zheng and said they had no reports of him being beaten. The police office in Zheng's district in Shanghai would not answer questions. Two middle-school classmates who are now Shanghai vice mayors, Zhou Yupeng and Yang Dinghua, refused to comment on his situation.

In crowded China, land can be a sensitive thing. The government both owns it and decides how it can be used. Evictions for Olympics projects are an ongoing issue in Beijing, and Shanghai has cleared out hundreds of thousands of people in recent years to make way for high-profile projects. Property quickly turns political.

In the eyes of the Shanghai government, Zheng went too far. He claimed Shanghai's highest official, Communist Party Secretary Chen Liangyu, was tied to illegal land deals that resulted in forced evictions. Then he contacted an overseas human rights group, Human Rights in China, about forced evictions and was jailed for "illegally providing state secrets to entities outside of China."

He was released in 2006 after serving three years.

Zheng first became interested in the law and property rights when he himself was homeless. Sent to the far north for 11 years of army corps work during the upheaval of the 1967-77 Cultural Revolution, he returned to Shanghai, where apartments were scarce and the government decided who got them. Zheng moved from place to place, staying with friends.

He worked at an underwear factory and taught himself law at night. He became a lawyer in 1993 and started acting for evicted Shanghai residents.

Later, at his trial, he would tell the court emotionally: "I was born poor and could understand the poor people's situation and how even the most basic freedoms could be taken away."

He was disbarred in 2001, for reasons the government has never explained. He assumes it was because of the almost 500 eviction cases he worked on, "which really offended the Shanghai government." He appealed, but there has never been a judgment.

Then, in 2003, he agreed to help with a case so sensitive that he said, "I'll go to jail for this one."

Some Shanghai residents sued a wealthy downtown district and accused local officials of taking bribes from a developer for the land on which they lived. Zheng said he had evidence tying the project to communist boss Chen. Zheng claimed Chen's younger brother partnered with real estate tycoon Zhou Zhengyi in getting development rights on the land for free.

Soon after making his accusations against Chen, Zheng was sent to prison.

Last month, the party boss was sentenced to 18 years in prison as part of a massive, unrelated corruption investigation that brought down a number of Shanghai city leaders, including the tycoon, Zhou.

Zheng is still pushing to reform China's legal system. He fills notebooks and diaries with his legal opinions and welcomes visitors who need advice. From time to time, he slips articles to friends who publish them on Chinese-language Web sites overseas.

"To some degree, we're both a little crazy," said Zheng's own lawyer, Beijing-based Pu Zhiqiang, who still hasn't been able to meet his client. "There are few lawyers like us who choose to help the helpless people against the authorities. It doesn't make money, but it makes lots of trouble."

Zheng and his wife live on her $200 monthly pension and $570 a month from Pu, his lawyer.

"Everything I'm wearing has been given to me by friends," Zheng said, tugging at his worn gray sweater. Friends pay for things like milk and the daily newspapers. Clients pay for his legal advice with boxes of pens.

Last summer, Zheng persuaded his 22-year-old daughter to move to New York, where she is studying English. She didn't want to go, but "she was told she had no future in China," Cohen, the professor, said.

Zheng told her it would be best not to return. He has no cell phone, and because his fixed-line phones are often monitored or disconnected, he hasn't spoken directly to her since she left.