A Queens motel frequented by underage prostitutes has been shut down and an employee arrested, capping a months-long investigation, the Queens district attorney’s office said yesterday.

Officials padlocked the Executive Motor Inn, a 44-room motel on North Conduit Avenue near John F. Kennedy International Airport earlier this month, after undercover cops posing as prostitutes and customers found it to be a hotbed of prostitution, the district attorney’s office said.

In a pre-dawn raid December 10, police arrested Bryant Erickson, 67, who worked as the motel’s night clerk. He allegedly permitted prostitutes to set up shop there.

Police also arrested Philip Dixon, 41, who allegedly was found in the company of a 15-year-old runaway he was said to have picked up two blocks away. On December 21, officers padlocked the motel, shutting it down at least temporarily.

The investigation was a cooperative effort between the district attorney’s office, the New York City Police Department, and the city’s Department of Building and Department of Finance, the district attorney said. It resulted in at least 12 other arrests within the past year, addressed what the district attorney called the blatant prostitution that has plagued the neighborhood and earned the motel a corrupt reputation.

“It was not run as a motel, but rather as an unabashed brothel catering to pimps and prostitutes – some of whom were underage and runaways,” the Queens district attorney, Richard Brown, said in a statement yesterday.

The motel had been under surveillance over the past few months, the disrict attorney’s office said. During the course of the investigation, a male undercover detective posing as a customer allegedly was directed to a 1 a.m. appointment with a “hooker,” the district attorney’s office said. In another instance, the office said, a female undercover officer posed as a prostitute and asked the night clerk to direct clients to her. He advised her that it was illegal but did so anyway, the district attorney’s office said.

According to a law enforcement source, “dates” started at $100.

As far back as June, area residents urged officials to target local prostitution, and held a meeting with the district attorney, the chairwoman of Community Board 12, Gloria Black,said. The increasingly frequent presence of prostitutes and pimps on residential streets threatened homeowners, who wanted clean blocks, “just like any other decent neighborhood,” Dr. Black said.

According to the Queens district attorney’s figures, 150 girls under 17 were arrested for prostitution in New York City in 2004 – 53 of them in Queens. Statistics from the Department of Criminal Justice Services indicate that in 2004, Queens County’s prostitution-related arrests rose to 1,960 from 1,554 the year before.

Yesterday, City Council Member David Weprin, a Democrat representing the Queens district adjacent to the motel, praised the arrests and said he hopes the motel is shut down permanently. “Clearly it’s something that’s been happening in the area,” he said. He said he also hopes the investigation deters pimps from reopening elsewhere in the area.

An attorney representing Executive Motor Inn Incorporated, the corporation that owns and operates the motel, denied there was systemic criminality at the property and argued yesterday that closing the motel was a drastic measure. If any wrongdoing took place, it was “one rogue clerk at night” who violated a corporate policy prohibiting prostitution, drugs, and other unlawful activities, the attorney, John Ryan, said. He noted that shutting the motel was “harmful to the business itself,” which he said was run legitimately. He said that at the time the motel was shut down, nearly 80 legitimate guests were registered.