Beijing prosecutors had approved a police application to arrest Liu Hu, a journalist suspected of fabricating rumors online, Beijing News reported on Oct 10.
But prosecutors did not announce what crime Liu is charged with, the report said.
Zhou Ze, Liu's lawyer, said on his micro blog that Liu was arrested for defamation, according to the report.
Before Liu's detention in August, Liu, working for a newspaper in Guangdong province, used his real-name Sina micro blog account to make corruption allegations against Ma Zhengqi, vice-minister of the State Administration for Industry and Commerce.
It is unknown whether Liu's arrest is related to his online reports.