At a glance, it looked like an irresistible bargain. An unidentified man in the lobby of the D.C. Human Services office at 122 C St. NW was selling $30 March parking permits -- no questions asked -- for the parking garage next door at the U.S. Labor Department.

But before the month had ended, plenty of questions were being asked. The permits were all counterfeit.

In the last two weeks, Federal Protective Service (FPS) investigators have recovered about 25 bogus parking permits from Labor Department garages. All had the same control number -- 0811 -- a number that doesn't exist on the estimated 1,500 legitimate permits, investigators said.

"It was a good job, but they didn't fool everybody for very long," said John Zintack, vice president of operations for Doggett Enterprises, the private subcontractor managing the garages.

In the course of the investigation, most of the holders of bogus permits were found to be employes at the Department of Human Services.

"Most people said they bought them from a man in front of 122 C St. One lady said someone just walked up to her on the street and said, 'Do you want to buy a parking permit?'" recalled Kenneth A. Morrison, one of the investigators. He said no arrests have been made but the investigation is continuing.

Morrison said parking lot customers normally obtain the $30 permits by filing an application with the garage parking manager. But all the garages have long waiting lists and require that permit holders form car pools. The cost of parking at private lots in the area runs about $80 a month, he said. Thus the $30 offer for space at one of the three Labor Department garages was understandably attractive.

"I believe they knew they were purchasing illegal permits," Morrison said. "But they didn't think they were bogus. They thought they were just purchasing hot [stolen] permits."

Morrison said he first sensed a problem early in March when cars began popping up in unusually large numbers at the garage at 3rd Street and Constitution Avenue NW. Cars were everywhere -- in the parking spaces for the handicapped, leading down the ramps, doubled up in the aisles. On one day alone, Morrison said, he wrote 38 tickets for illegally parked cars. Then he noticed something else: Most had the same control number on their permits.

"We had complaints from people who would leave to attend business outside the Labor Department and then couldn't get back in [the garage]," said Robert Kammer, the Labor Department's general services manager. An official complaint was made to FPS and the investigation was started.