It was not the usual crowd that notoriously selective Steve Rubell lets into Studio 54, the trendy disco he coowns in New York.

But at 9:30 yesterday morning not many hours after Studio 54's usual closing time, 30 special agents of the criminal investigation division of the Internal Revenue Service were on the doorstep. Their conservative garb was not the usual disco attire, but with their court-authorized search warrant, they conducted a raid.

"We found what we wanted," said an IRS spokesman, referring to financial records and documents.

And in the way of most things at Studio 54, the unexpected happened. In walked Ian Schrager, co-owner and co-founder of Studio 54 (with Rubell and Jack Dushay). Schrager dropped the books he was carrying on the floor, and the agents picked them up.

According to assistant U.S. attorney Peter Futler, agents found five packets of cocaine tucked inside the books. Schrager was arrested and charged with possession with intent to distribute. He's out on $50,000 bail, according to Futler.

And like most major events at Studio 54, the television cameras were standing by. The way Rubell describes it, "Camera crews were alerted to an accident on 54th street (one block away), and not finding anything, turned to the excitement at Studio 54."

Agents were on the premises all day yesterday. Rubell said last night he handed over everything voluntarily.

Roy Cohn, his lawyer, persuaded a federal judge to order the agents out by the end of the day. The former counsel to the late Sen. Joseph McCarthy's investigative subcommittee said, "They arrived with guns and crowbars. It sounds like Nazi Germany," and later added, "I've never seen McCarthyism practiced this way."

Studio 54 was open for business as usual last night.

"When you are in the public eye, you expect to be harassed," said Rubell, obviously feeling harassed.