(Reuters) - A divided federal appeals court on Tuesday blocked what would be the nation's first supervised drug-injection site from opening in Philadelphia, saying it ran afoul of a federal law originally passed to shut down drug dens.

"Though the opioid crisis may call for innovative solutions, local innovations may not break federal law," wrote Judge Stephanos Bibas of the 3rd U.S. Circuit Court of Appeals, siding with U.S. Attorney William McSwain of the Eastern District of Pennsylvania, who had sued to block the site.

The decision overturned a lower court ruling in favor of Safehouse, a non-profit that aims to open a facility where drug users can safely inject heroin, fentanyl or other drugs in the presence of medical professionals who could treat them for overdoses.

"The 3rd Circuit's opinion is a faithful reading of the statute's plain language and is consistent with Congress's intent to protect American neighborhoods from the scourge of concentrated drug use," McSwain said in a statement.

"We are disappointed" with the decision, said Ilana Eisenstein of DLA Piper, who represents Safehouse. "We remain confident that the law was not intended to force Americans to stand by as idle witnesses while our brothers and sisters are dying. Conscience compels us to pursue all legal options, and we shall."

Safehouse had announced that it intended to open the facility in 2018, prompting McSwain's office to file a lawsuit in Philadelphia federal court seeking an injunction to block it.

The government pointed to a provision of the Controlled Substance Act commonly known as the "crack house statute," which makes it a crime to knowingly open or maintain a place for distributing or using controlled substances.

In February 2020, U.S. District Judge Gerald Austin McHugh in Philadelphia ruled in favor of Safehouse, but later issued a temporary order blocking the site from opening during the government's appeal.

Bibas agreed with the government. He said that while the federal statute had been intended to shut down crack houses, "its words reach well beyond them" to encompass Safehouse, despite its "benevolent motive," by making it a crime to open a property for others to take drugs.

"Safehouse admirably seeks to save lives," Bibas wrote. "And many Americans think that federal drug laws should move away from law enforcement toward harm reduction. But courts are not arbiters of policy. We must apply the laws as written. If the laws are unwise, Safehouse and its supporters can lobby Congress to carve out an exception."

Circuit Judge Thomas Ambro joined in the opinion.

Circuit Judge Jane Roth dissented, saying the majority had wrongly interpreted the crack house statute. She said the Safehouse's purpose was not drug use, but rather drug treatment, and that the majority's interpretation would create excessively broad criminal liability.

"As Safehouse correctly argues, under the majority's construction, parents could violate the statute by allowing their drug-addicted adult son to live and do drugs in their home even if their only purpose in doing so was to rescue him from an overdose," she wrote.

The case is USA v. Safehouse et al, 3rd U.S. Circuit Court of Appeals, No. 20-1422.

For the government: U.S. Attorney William McSwain of the Eastern District of Pennsylvania

For Safehouse: Ilana Eisenstein of DLA Piper