Authorities arrested four people suspected of prostitution-related crimes Wednesday after searching the Tokyo Massage parlor west of Casper.

The arrests followed a several-month investigation involving local, state and federal law enforcement agencies, Natrona County Sheriff's Sgt. Mark Sellers said Thursday.

Law enforcement officers also searched an apartment on West Ninth Street in Casper on Wednesday afternoon as part of the investigation, which is ongoing.

"We recovered a lot of documents that we're going through and we'll be conducting a lot of interviews of possible customers that were out there," Sellers said.

Tokyo Massage, which has long been rumored to offer services that go beyond a mere back rub, appeared deserted when visited Thursday morning by a Star-Tribune reporter.

The parlor sits in plain view along U.S. Highway 20/26, just east of Natrona County International Airport. A placard over the building's entrance advertises "sauna" and body shampoo" services offered 24 hours, seven days a week.

Plywood covered all of the windows and an adjacent garage appeared to be designed to offer customers a discreet place to park. Signs posted on the doors said "Closed by order of the sheriff. No trespassing."

No one picked up Thursday at the phone number listed for the parlor.

Authorities identified the four people they arrested as Okki Shoffler, 53, Kyong Stodolka, 57, June Wilhelmi, 60, and Kenneth Robertson, 60. Sellers said the arrests were related to the business. He did not elaborate.

Stodolka, Wilhelmi and Robertson were booked on suspicion of promoting prostitution, jail records show. Shoffler was booked on suspicion of prostitution.

All four remained held Thursday at Natrona County Detention Center. They were expected to make their intial court appearances this morning in Natrona County Circuit Court.

In Wyoming, prostitution and solicitation are misdemeanors. Promoting prostitution is a felony.

Sellers declined comment when asked what prompted the Wednesday searches of Tokyo Massage and the West Ninth Street apartment.

The investigation into the massage parlor involved the Natrona County Sheriff's Office, the Wyoming Division of Criminal Investigation, U.S. Immigration and Customs Enforcement and the Federal Bureau of Investigation.

Natrona County records list the owners of the Tokyo Massage property as Bruce and Terrie Miller of Littleton, Colo., along with James A. Eye Jr. The 31,363-square-foot building was constructed in 1970.

In an interivew Thursday with the Star-Tribune, Miller said he and his wife have been trying to sell the property for years because of its massage parlor status, and because of a nearby dilapidated house formerly used as a residence by Eye, his former business partner.

During a disagreement between the partners, Miller claims Eye started the massage parlor business without his authorization. Eye allegedly found people for the massage business, remodeled the office area and installed massage tables.

Miller said he hasn't seen or talked to Eye for at least a decade, and believes his former partner moved somewhere to the southeastern United States.

Efforts to locate Eye were unsuccessful.

Miller also said he hasn't visited the Casper area in 18 months.

Miller said he doesn't like the massage parlor business that's been operating on his property.

"Common sense will tell you you can get something in there besides a massage," he said.

Reach crime reporter Joshua Wolfson at (307) 266-0582 or at josh.wolfson@trib.com. Reach county reporter Tom Morton at (307) 266-0592 or at tom.morton@trib.com.