KENNEBUNK —  Neighboring tenants took notice when a constant stream of men, some dressed in sports jackets and other business attire, entered the back door of the small office building that housed the Pura Vida/ZUMBA Studio.

Some of the men carried gym bags, others arrived empty-handed. During the half-hour to an hour that each one stayed, the owner of the hair salon downstairs heard “a lot of moaning and groaning,” according to a police affidavit filed Monday in Biddeford District Court.

The document details allegations that a woman from Wells charged the men for sex, secretly video recorded their encounters and provided their license plate numbers to an insurance agent and private investigator from Thomaston who had access to the state’s motor vehicle database.

The agent, Mark G. Strong, 56, was arrested Tuesday on charges of promotion of prostitution. He was released from the Knox County Jail after posting $5,000 bail.

No charges have been brought against the woman, identified in the affidavit as Alexis Wright.

Kennebunk police said Wednesday that they expect additional charges to result from the months-long investigation, which involved several police agencies in southern Maine and federal law enforcement officials.

Police said they got anonymous phone calls about suspicious activity at the Pura Vida/ZUMBA dance studio in September, when it was on York Street. Workers at nearby businesses told officers that men would arrive at the dance studio at all hours, then leave a short while later.

After Wright moved the dance studio to High Street, her landlord noticed the same frequent arrivals and departures, the affidavit says. The building owner said he did an Internet search for Wright and found a site with a video of her performing a sex act. He told police that the video appeared to have been recorded in the space he was leasing to Wright.

In February, police got search warrants for the York Street site, the High Street site and Wright’s home in Wells. The arrest affidavit says they found electronic client ledgers including “meticulous records” of her sexual encounters and a monetary value assigned to each.

The warrants issued for the searches have been sealed at the request of the York County district attorney.

Police said the records suggest that Wright earned about $150,000 from the sex acts. No time period is mentioned for when she would have made that money, but Wright originally received a permit for the dance studio on York Street in March 2010.

The affidavit says Wright contacted Strong before clients arrived, sent some of the videos of her encounters with them to Strong, and provided him with license plate numbers, suggesting that he “run them.”

Strong is a licensed private investigator in Maine so he had access to the Bureau of Motor Vehicles’ database to identify people, using their car registration numbers, according to the affidavit.

The affidavit does not allege any effort to extort money from any of the men. It says police linked Strong and Wright through postal, telephone and bank records.

Police are releasing few other details.

Kennebunk police Lt. Anthony Burpee said there hasn’t been an arrest on prostitution charges in the town in the 14 years he has been on the force.