LINCOLN, Neb. (AP) — State Sen. Ernie Chambers has filed a complaint that could trigger a legislative hearing on Nebraska’s lethal injection protocol.

Chambers submitted the complaint Wednesday to the Legislature’s Executive Board.

Chambers contends the Department of Correctional Services has violated state and federal laws and that its lethal injection protocol is unconstitutional.

The complaint follows the American Civil Liberties Union of Nebraska’s allegations that prison officials may have violated federal laws in obtaining execution drugs.

Prison officials say they were purchased legally. Gov. Pete Ricketts has accused the ACLU of fabricating charges.

Chambers is invoking a law that requires the Executive Board’s chairman or a staff member to refer his complaint to a legislative committee. Chambers says the Judiciary Committee should investigate it.

Chambers sits on the committee. He opposes capital punishment.