BILLINGS, Mont. (AP) — A judge has sanctioned the state of Montana over its delay in complying with a court demand to turn over documents that could reveal if there was manipulation of an expert witness in a case that halted lethal injections.

Montana Department of Justice spokesman Eric Sell said Tuesday that the agency had turned over the documents in response to the sanctions order from Judge James Reynolds.

They were given to the court and attorneys for the plaintiffs in the case: Ronald Smith and William Gollehon, Montana's only two death row inmates.

The American Civil Liberties Union of Montana, which is representing Smith, has questioned whether the testimony of expert witness Roswell Evans was manipulated at trial to bolster the state's unsuccessful claim that the drug pentobarbital was suitable for use in executions.

Sell says there was no manipulation by the state.

Smith and Gollehon sued Montana in 2008, challenging the constitutionality of its lethal injection statute. The suit focused on the state's plans to use pentobarbital in lethal injections after the Department of Corrections was no longer able to obtain sodium pentothal, the original barbiturate used in the state's two-drug execution protocol.

Evans had testified in 2015 that the drug pentobarbital met a state law requirement that an "ultra-fast-acting barbiturate" be used in lethal injections. But he also testified in a separate case in Tennessee that the drug was not classified as ultra-fast acting.

After rejecting Evan's testimony in the Montana case, District Judge Jeffrey Sherlock ruled pentobarbital did not comport with state law, which effectively blocked executions in the state.

The state later investigated the testimony and told the ACLU that it had terminated its dealings with Evans, but it did not turn over the documents associated with the investigation.

ACLU legal director Alex Rate said the organization would be reviewing the documents to determine if further sanctions or other actions are warranted.

Reynolds also ordered the state to cover some of the plaintiffs' attorney fees as punishment for not turning over the documents more quickly.

The documents were originally ordered released on Dec. 12, 2016, but the state sought a protective order that would prevent the plaintiffs from further disseminating the information.

Reynold rejected the request for the protective order and said in a Dec. 12 ruling that the state's arguments for delay were "not well-founded" and were deserving of sanctions.


Follow Matthew Brown on Twitter at .