COVINGTON, La.—Five years ago, Hurricane Katrina gave the Benedictine monks at St. Joseph Abbey a new calling.

After the storm pummeled much of a pine forest they had long relied on for timber and income, the monks hatched a fresh plan: They would hand-craft and sell caskets.

But now, local funeral directors are trying to put a lid on the monks' activities. The state funeral regulatory board, dominated by industry members, is enforcing a Louisiana law that makes it a crime for anyone but a licensed parlor to sell "funeral merchandise." The morticians are serious. Violators such as the monks can land in jail for up to 180 days.

"I don't relish that thought," said Abbot Justin Brown, head of the 107-year-old abbey, as he sipped coffee in the monastery on a recent misty morning.

St. Joseph's 36 monks, whose pastimes include baking raisin bread for the homeless, are putting up a fight. On Aug. 12, they filed a lawsuit in federal court in New Orleans to try to overturn the state edict. In the filing, the monks argue that the state law violates their right to pursue a gainful occupation. "We're not just going to sit back and let these guys bulldoze us," says Deacon Mark Coudrain.