The man accused of holding three young US women captive for around a decade in a house in Cleveland will plead innocent to charges of rape and kidnapping, one of his lawyers said Wednesday.

"There will be a plea of not guilty," attorney Jaye Schlachet told AFP.

He would not say on what grounds Ariel Castro will plead not guilty in the case that has shocked America, urging the public to refrain from a rush to judgment.

"He's not a monster and he shouldn't be demonized by the media," the lawyer said.

The 52-year-old Castro, who is being held on an $8 million bond, has been charged with kidnapping and raping three women over around a 10-year period, one of whom bore his child in captivity.

Prosecutors say they also may charge him with the aggravated murder of unborn babies at least one of the women lost during beatings, a crime that could carry the death penalty.

Michelle Knight, 32, Gina DeJesus, 23, and Amanda Berry, 27, were freed on May 6 after a neighbor heard Berry call for help and kicked in the door to Castro's house in a working-class Cleveland neighborhood.

"All the evidence will be disclosed at the court proceedings," Schlachet said. "I would ask the community not to rush, to consider everything before expressing an opinion."