Twenty-two inmates filed the original lawsuit in 2001. Some of them claimed they were stripped and held in solitary confinement after being jailed for misdemeanor offenses.
In newly filed court documents, inmates claim that guards sprayed their genitals with Mace, "hog-tied" them and kept groups of 12 naked in frigid cells steeped in pools of bodily fluids.
An attorney for the inmates says more than 100 inmates have been mistreated at the jail, and the total eventually could surpass 200.
The Justice Department, FBI and the US Attorney's Office began a criminal investigation even before the latest claims were filed.
Sheriff Charles Brown has denied the allegations.