ANCHORAGE -

Gov. Sean Parnell has requested a federal investigation of sexual abuse allegations which have rocked the Alaska National Guard, citing existing cases which have been dropped by law enforcement.

In a Feb. 28 letter to National Guard Bureau Chief Gen. Frank Grass (PDF), released Wednesday by Parnell’s office, the governor asks the nation’s highest-ranking National Guardsman to appoint an investigator to examine both “open and closed investigations related to reports of sexual assault, rape, and fraud among members of the Alaska National Guard.”

"I am extremely proud of our Alaska National Guard members and their professionalism in carrying out their duties," Parnell wrote. "However, I remain deeply concerned by reports of sexual assaults and other behavior creating a hostile environment and culture within portions of the Alaska National Guard. Not only are individuals victimized and traumatized in these circumstances, but collectively our National Guard is harmed -- from morale to mission damage."

The request comes after state Sen. Hollis French (D-Anchorage) asked Parnell to determine how many sexual assault complaints about Alaska National Guardsmen were made between 2008 and 2012. Guard leadership has admitted that 29 cases of sexual assault have been reported since 2009, with 21 closed or suspended after law enforcement got involved.

Although Parnell praises the performance of Alaska National Guard Adjutant Gen. Thomas Katkus in creating systems to investigate cases and encourage their reporting, he tells Grass the situation warrants a closer look.

“Information I recently learned, however, compels me to write and seek an outside look at our Alaska National Guard's training, reporting, investigations, and case dispensation practices related to the areas I outlined above,” Parnell wrote. “Where a number of matters were referred to civilian law enforcement who declined to investigate, I ask you to review those matters, as well.”

In the letter, Parnell promises any federal investigator "full cooperation from all units, guardsmen and women, and civilians within the Alaska Department of Military and Veterans Affairs who are under my authority." He also designates his chief of staff, Mike Nizich, as a point of contact with Grass on the investigation.

This is a developing story. Please check KTUU.com and the Channel 2 newscasts for updates.