Authorities in southern China on Friday released a pioneering newspaper editor whose arrest five months ago sent a chill through the nation's increasingly independent-minded newsrooms and prompted a campaign on his behalf by journalists, lawyers, writers and retired officials.

Cheng Yizhong, 39, the former executive editor of the Southern Metropolis Daily in the coastal city of Guangzhou, returned home at about 10 p.m. and appeared to be in good health, according to a source close to his family. But it was not clear if conditions were placed on his release or whether he would be permitted to return to the newspaper.

"We hope all those officials who defy the progress of time and, for their own selfish interests, try to suppress freedom of speech and social conscience have learned a lesson," Xu Zhiyong, one of Cheng's lawyers, said in a statement posted on his Internet site. "We hope they won't manufacture absurd cases of injustice again. We hope they won't damage China's image again."

Cheng was arrested March 19 in a corruption probe that party sources said was a veiled act of retaliation by local officials who were upset by the newspaper's aggressive reporting. The sudden decision to release him instead of putting him on trial underscored divisions in the ruling Communist Party about the creeping expansion of media freedoms.

The government owns and controls China's newspapers and television stations, but the limits of permissible news coverage are becoming increasingly blurred as journalists and others in the party argue that a more assertive press can help the leadership fight corruption and improve governance. Market reforms have also given state media outlets an incentive to report real news instead of propaganda.

Cheng, who built the Southern Metropolis Daily into one of the country's most daring -- and profitable -- newspapers, was on the cutting edge of this change. Last year, the tabloid published an investigative report about the death of a young college graduate in police custody that sparked nationwide outrage and led Beijing to abolish a long-entrenched system of detention camps.

But the report also angered local party officials in Guangzhou, the capital of Guangdong province, who responded by ordering an investigation into the newspaper's finances. One day before Cheng's arrest, the Daily's general manager, Yu Huafeng, and another executive, Li Minying, were convicted on what appear to be trumped-up corruption charges and received 12- and 11-year prison sentences, respectively.

Supporters of the newspaper quickly launched a campaign against the crackdown that included a news conference in Beijing, a petition drive on the Internet and a series of quiet appeals within party channels. Among those who spoke out on behalf of Cheng and his colleagues were three retired party leaders in Guangdong, sources said.