NYPD is investigating a drug manufacturing lab inside a W. 54th St. co-op

Police are investigating the possibility that a drug manufacturing lab was being run out of a Hell’s Kitchen co-op, sources said Monday night.

The building on W. 54th St. between Ninth and Tenth Aves. is less than two blocks from the NYPD’s Midtown North precinct stationhouse.

Authorities swarmed the co-op about 6:30 p.m. after residents told cops they believed that a tenant was producing methamphetamine inside the five-story walkup, police sources and neighbors said.

But the sources said investigators now believe the suspected crystal cooker was actually making bath salts — a mind-bender that has surged in popularity in the U.S. and has been linked to dozens of violent incidents

Investigators were questioning a shaggy-haired suspect in his 40s whose cluttered third-floor apartment reeked of ammonia and cat urine, police sources and neighbors said.

“He looked like a lumberjack,” said Chelsea Blakeburn, who watched the man being escorted out of the building by police.

One cop source at the scene was less endearing.

“It’s a real s--thole in there,” the source said. “This guy has got a real drug problem.”