HOULTON, Maine (AP) — The American Civil Liberties Union has filed a lawsuit against the Maine Department of Corrections on behalf of an inmate who says he was denied medication to treat his opioid addiction.

The lawsuit filed Thursday says the department is violating 30-year-old Zachary Smith's rights under the Americans with Disabilities Act, and their actions amount to cruel and unusual punishment.

Smith uses Suboxone, also known as buprenorphine. His lawyer says he was denied the medication at Aroostook County Jail earlier this year, and was told he could not use the medication if he goes to state prison.

Maine ACLU legal director Zachary Heiden says denying needed medication to people with opioid use disorders undermines the goal of keeping them off opiates.

The department of corrections commissioner has declined to comment.