The trial of prominent Shanghai lawyer Zheng Enchong on charges of 'illegally providing state secrets to entities outside of China' will begin tomorrow, a human rights group says. Officials have declined to give details about the charges. But before his detention on June 6, Zheng, who acted as an adviser to residents fighting efforts to relocate them, was in contact with human rights groups, overseas journalists and diplomats. The Shanghai No2 Intermediate People's Court would hear the case, which would be closed to the public, New York-based Human Rights in China said. The group said Zheng maintained his innocence and believed he was arrested because he had offended powerful local interests in a lawsuit alleging corruption in the transfer of land in Jingan district to developer Chau Ching-ngai. Mr Chau is reportedly under detention amid an investigation of his financial dealings. Two groups of residents who brought lawsuits against Jingan officials over the transfer of land off Beijing Road and the level of compensation they were offered lost their cases last week. Zheng was advising on those cases. Shanghai stripped Zheng of his law licence in 2001, but he continued to offer legal advice to evicted residents, advising on more than 500 such cases. Zheng's lawyers are Guo Guoting and Zhang Sizhi, who has previously represented political dissidents in court. In the wake of the property scandal, Shanghai pledged to review all land deals for the past two years and implement a bidding system for land sales. Local authorities have offered more compensation, while at the same time cracking down on a string of public protests.