Cho, who served as commissioner-general from 2010-2012, is accused of mobilizing National Police Agency units to write more than 40,000 Internet comments in an effort to help form positive public views of the Lee administration.
It was his second questioning, following the first a week ago.
After arriving at the National Police Agency, Cho refuted the allegations.
"I instructed police across the nation to respond actively to those denouncing police with false facts and I also ordered this officially during an open meeting," Cho told reporters. "How can this constitute political maneuvering and opinion-rigging?"
Some former ranking police officers under Cho's leadership have also been investigated, although a court has denied a police request for arrest warrants for them on charges of abuse of power and violation of telecommunications law. (Yonhap)