LINCOLN, Neb. (AP) — A German pharmaceutical company has filed a lawsuit to prevent Nebraska from using lethal injection drugs next week in what would be the state's first execution in more than two decades.

The federal lawsuit filed late Tuesday could delay the Aug. 14 execution of Carey Dean Moore, who was sentenced to death for killing two Omaha cab drivers in 1979. The company, Fresenius Kabi, opposes the use of its drugs in executions and alleges that the Nebraska Department of Correctional Services' supply of potassium chloride was made by the company.

Moore has stopped fighting the state's efforts to execute him , leaving death penalty opponents with no real options other than to hope a drug manufacturer challenged the state's use of its products. In Nevada, a judge indefinitely postponed an execution last month after drugmaker Alvogen filed a similar lawsuit over one of its products.

Nebraska state officials have refused to identify the source of their drugs, but Fresenius Kabi alleges the state's supply of the drug is stored in 30 milliliter vials. Fresenius Kabi said it's the only company that supplies potassium chloride in vials that size. The company said it may also have manufactured the state's supply of cisatracurium, and that Nebraska's use of its drugs would damage its reputation and business relationships.

"While Fresenius Kabi takes no position on capital punishment, Fresenius Kabi opposes the use of its products for this purpose and therefore does not sell certain drugs to correctional facilities," company attorneys wrote in the lawsuit.

The company said it only sells those products to wholesalers and distributors who sign a contract agreeing not to supply the drugs to correctional departments.

"These drugs, if manufactured by Fresenius Kabi, could only have been obtained by (the corrections department) in contradiction and contravention of the distribution contracts the company has in place and therefore through improper or illegal means," the company said in the lawsuit.

In a statement, a spokeswoman for Nebraska Attorney General Doug Peterson said the lethal injection drugs were purchased lawfully "and pursuant to the state of Nebraska's duty to carry out lawful capital sentences."

A spokeswoman for the Nebraska Department of Correctional Services did not immediately respond to a request for comment.

Nebraska has never carried out an execution by lethal injection, and the state plans to use an untried combination of four drugs during Moore's scheduled execution. The state's last execution, in 1997, used the electric chair, which the Nebraska Supreme Court later declared unconstitutional.

Nebraska's current execution protocol calls for four drugs: the sedative diazepam, commonly known as Valium, to render the inmate unconscious; fentanyl citrate, a powerful synthetic opioid; cisatracurium besylate, which induces paralysis and halts the inmate's breathing; and potassium chloride to stop the heart.

The American Civil Liberties Union of Nebraska, a leading death penalty opponent, praised the company's intervention and chastised the state for refusing to release documents identifying the supplier. State officials have done so in the past without objection.

"While more states are turning away from the death penalty, Nebraska officials are rushing to carry out an execution cloaked in secrecy with an untested four-drug scheme that carries immeasurable risks for unnecessary pain and a botched execution," said Danielle Conrad, the group's executive director.

The lawsuit is not Nebraska's first run-in with Fresenius Kabi. Last year, a company spokesman told The Associated Press that state officials had obtained a batch of its potassium chloride in 2015 because one of its distributors made a mistake.

A company spokesman said at the time that Fresenius Kabi discovered the sale through an internal audit and requested that the Department of Correctional Services return the drugs, but state officials never did. Those drugs expired in January 2017.GRANT SCHULTE, AP

[cover photo via]