The state Department of Public Safety confirmed Friday that the attorney general is investigating the warden of Hawaii’s only women’s prison.

Mark Patterson was placed on leave at 4:30 p.m. Aug 12, pending the outcome of the investigation, said Martha Torney, deputy director of administration at the public safety department. She said she did not know whether the leave was unpaid and could not discuss the investigation.

Milton Kostubo, a supervisor from the department’s intake service center, was appointed acting warden of the Women’s Community Correctional Center in Kailua.

Torney said the department could do a separate administrative investigation after the attorney general’s investigation is complete, but that does not seem necessary at this time.

Joshua Wisch, special assistant to the attorney general, declined to comment on the investigation.

In 2008, Patterson was credited with turning the prison around and recognized as the department’s manager of the year. At the time, the department said with Patterson in charge, prison officers were getting needed training, sick calls were down, and the quality of work and morale improved.

He was also recognized in Yes! magazine in June for promoting therapeutic treatment and other innovations like hydroponic gardening for inmates.

Patterson became chief of security at the prison in 2006 after the acting warden and six other prison staff members were placed on leave during an investigation by the attorney general. Media reports at the time said the prison security chief, Malcolm Lee Sr., said all the employees were cleared of criminal investigations and that the investigation was based on "an outright lie" about items being taken from the prison, such as air conditioners and plywood.

The prison, at 42-477 Kamehameha Highway, has an operating capacity of 260 inmates and houses 230.

Its history includes improvements after a lawsuit citing overcrowding and inadequate safety at the prison.

The American Civil Liberties Union filed the lawsuit in 1984, and the case was dismissed in 1997 in part because the facility was expanded.