Sacramento- A Sacramento city firefighter faces criminal allegations of sexual assault after he and several other firefighters attended an event called the “Porn Star Costume Ball” at the Radisson Hotel while on duty Friday night, authorities said.

The revelations came at a hastily assembled news conference Saturday attended by Sacramento Mayor Heather Fargo, City Manager Bob Thomas, Police Chief Albert Nájera and acting Sacramento Fire Chief Rod Chong.

The four read brief statements, saying authorities had launched two investigations: a police probe into the allegations of sexual assault and a separate investigation by Sacramento Fire Department officials into alleged inappropriate behavior by on-duty personnel.

Following their statements, the four refused to answer questions or to provide details of either the sexual assault allegation or the alleged misconduct. They said several firefighters have been placed on administrative leave while the investigations continue, but would not say how many firefighters were involved or what they were doing at the event.

However, sources familiar with the investigation say the probe involves six on-duty firefighters who rode to the event in two Fire Department rigs – including an engine. According to the sources, the alleged sexual assault took place inside one of the vehicles.

Sources said some of the firefighters were caught on videotape engaged in inappropriate behavior during the party, but would not elaborate.

The investigation began shortly after 1:15 a.m. Saturday, when a woman who attended the party reported to police that she had been sexually assaulted.

“We don’t know what (the firefighters) were doing there,” said Fire Chief Chong. “We’re still really in the early stages of this investigation.”

Radisson Hotel General Manager Randall King said that on-duty firefighters frequently stop at the hotel at 500 Leisure Lane when there are concerts or large events to check on fire safety conditions.

“They’ve always been very well-behaved,” King said. “I’ve never seen any drinks in their hands.”

Asked about King’s statement, Chong said the department does send fire prevention officers to check on large events, but that what happened Saturday “was not a normal situation.” He would not elaborate.

James Mondragon, owner of Dub Star Universal, the company that organized the “Porn Star” ball, said he was unaware of the incident. Despite the name of the event, Mondragon said, the party did not involve any stripping or sexual acts. The idea was to get people to dress up, he said.

“The word ‘porn star’ is just to get your attention, but it wasn’t because there was any sex there,” Mondragon said. “There were just massive amounts of people dancing and having a good time.”

Teri Weigel, a former Playboy magazine centerfold who has appeared in adult videos, acted as a host for the event, organizers said. Several other adult video stars were in the attendance. About half of the 1,800 guests were dressed in “porn star” costumes, Mondragon said. He said many of the women were scantily dressed, wearing pigtails and heavy makeup.

The sexual assault allegation is the third scandal to emerge from the Sacramento Fire Department in the past two years. In October, firefighter Michael Roper was charged with selling steroids.

Roper was featured on the “September” page of the 2004 “Feel the Heat” Sacramento-area firefighter calendar, wearing his firefighter’s pants and suspenders over a bare chest. He was selected for the calendar after he and another city firefighter, Jeff Rempfer, performed a striptease during a talent competition at the Radisson Hotel. Roper since has been dismissed from the fire service and faces trial in Placer County.

Two years ago, a female firefighter at Station 6 in Oak Park said she was sexually harassed. Despite a lengthy investigation by city authorities, the allegations have not been resolved.

City Councilman Jimmy Yee said in a telephone interview that the council had been briefed Saturday on the latest investigation.

“I’m very surprised,” Yee said. “The Police Department and Fire Department are held in high esteem. To hear what allegedly happened is very disappointing.”

The “Porn Star” party criminal investigation will be conducted by the Police Department, Nájera said. The Fire Department also will conduct administrative hearings to determine whether firefighters acted unprofessionally, City Manager Thomas said.

The investigations will be monitored by Don Casimere, the city’s police accountability officer, who will submit his report to the City Manager’s Office, Thomas said.

“We have moved very quickly on this,” Nájera said. “It is going to be very complex and we have a lot of people to talk to.”