KANSAS CITY, Mo. — A reporter whose stories have been critical of Missouri’s death penalty procedures sued the state’s prisons chief Wednesday in federal court, accusing him of wrongly excluding him from being an execution witness.

The American Civil Liberties Union’s lawsuit filed on behalf of Buzzfeed News reporter Christopher McDaniel asks a judge to block anyone other than Missouri’s attorney general from serving as an execution witness until McDaniel’s due-process claims are decided. None of the 25 Missouri death row inmates had been scheduled for execution as of Wednesday.

McDaniel, a former reporter for St. Louis public radio, applied in January 2014 to witness a Missouri execution “to ensure that executions are carried out in a constitutional manner,” according to the lawsuit. But McDaniel never got a response, and 17 executions have been carried out by the state since.

George Lombardi, who heads the state Department of Corrections, has “unfettered discretion” in deciding who, according to state law, may be among the at least “eight reputable citizens” to witness an execution, according to the lawsuit.

David Owen, a Missouri Department of Corrections spokesman, told The Associated Press by email that the department doesn’t publicly discuss pending litigation. Neither Nanci Gonder, a spokeswoman for the attorney general, nor Scott Holste, a spokesman for the governor, responded to requests for comment.

The lawsuit contends that McDaniel’s “unfavorable” reporting about the way Missouri executes prisoners may explain why he hasn’t been allowed to witness an execution. McDaniel’s stories since December 2013 have called into question such matters as how the state obtains its execution drugs and the state’s method of giving condemned inmates sedatives before their executions.

State records obtained by the ACLU through a May 2014 public records request and eventual litigation showed that applicants to be execution witnesses were denied if they “expressed a desire to ensure that executions were carried out properly and constitutionally,” the lawsuit alleges.

“Execution witnesses are an important check to ensure the department does not abuse its power. That check does not work when the department can choose to exclude anyone critical of its behavior,” Tony Rothert, the ACLU of Missouri’s legal chief, said in a statement.

Missouri has executed more prisoners than any state except Texas in recent years. It has executed 19 prisoners since November 2013, including six last year. The only one this year came in May, when 66-year-old Earl Forrest was put to death for the 2002 killings of two people in a drug dispute and a sheriff’s deputy in a subsequent shootout.