LINCOLN, Neb. — A federal judge on Friday refused to block Nebraska from carrying out the state's first-ever lethal injection despite a German pharmaceutical company's lawsuit that claims the state illicitly obtained its drugs.

U.S. District Judge Richard Kopf denied the company's request to temporarily block state prison officials from executing Carey Dean Moore, one of the nation's longest-serving death row inmates. Moore is scheduled to die Tuesday in Nebraska's first execution since 1997 with a never-before-tried combination of drugs.

Moore, who was convicted of killing two cab drivers five days apart in 1979, has stopped fighting the state's efforts to execute him. Kopf said granting the drug company's request would "frustrate the will of the people," referring to the 61 percent of Nebraska voters who chose to reinstate capital punishment in 2016 after lawmakers abolished it.

"I will not allow the plaintiff to frustrate the wishes of Mr. Moore and the laws of the state of Nebraska," Kopf said during the hearing.

Attorneys for the drug company, Fresenius Kabi, filed a lawsuit earlier this week arguing that state officials improperly obtained at least one of the company's drugs. Attorney Mark Christensen said the company plans to file an immediate appeal of Friday's ruling.

In Nevada, a judge indefinitely postponed an execution last month after drugmaker Alvogen filed a similar lawsuit over one of its products.

Moore is scheduled to be executed with a combination of four drugs: the sedative diazepam, commonly known as Valium, to render him unconscious; fentanyl citrate, a powerful synthetic opioid; cisatracurium besylate to induce paralysis and halt his breathing; and potassium chloride to stop his heart.

Fresenius Kabi argues that it manufactured the state's supply of potassium chloride and possibly the cisatracurium.

Nebraska state officials have refused to identify the source of their execution drugs, but Fresenius Kabi alleges the state's supply of potassium chloride is stored in 30 milliliter bottles. Fresenius Kabi said it's the only company that packages the drug in vials of that size.

Fresenius Kabi said Nebraska's use of its drugs would damage its reputation and business relationships. The company said it takes no position on capital punishment, but strongly opposes the use of its products for use in executions.

Nebraska death row inmate Carey Dean Moore is seen In this undated photo provided by the Nebraska Dept. of Correctional Services. Nebraska Dept of Correctional Services / AP

No other public evidence has surfaced to confirm the supplier's identity. A state judge in Nebraska ordered prison officials in June to release documents that might reveal the source of the drugs, but the state has appealed that ruling.

State attorneys deny Fresenius Kabi's allegation that prison officials obtained the drugs illicitly.

Assistant Attorney General Ryan Post said in court Friday that the state's interest in carrying out the execution outweighs the company's desire to protect its reputation. Post noted that the state still has not revealed its supplier, arguing that Fresenius Kabi could have remained anonymous by not filing the lawsuit.

"The plaintiff stepped right into the spotlight, and they're complaining about it," he said.

The state also notes that one of its protocol drugs expires on Aug. 31, which will leave the state with no way to carry out future executions .

In an affidavit filed Thursday, Department of Correctional Services Director Scott Frakes said he contacted at least 40 suppliers in six states and found only one that agreed to provide his agency with the necessary drugs. But that supplier is unwilling to sell them any more of its drugs, Frakes said.

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