Donald Zimmerman, inspector general of the Virginia Department of Corrections, said yesterday that he has initiated an investigation "on several fronts" into allegations about mismanagement and improprieties at the state's Camp 30 prison in Fairfax County.

Among the matters being investigated, Zimmerman said, is how inmates at the camp constructed a small, cabin-like visitors building there with highway department materials that were obtained without the department's approval.

"We are looking into that general area, among other things," said Zimmerman, the chief internal investigator for the department. The Washington Post yesterday quoted two inmates as saying they obtained the materials on a "midnight requisition" from an adjacent highway yard.

Zimmerman said yesterday he had initiated his investigation of the building last week after receiving an internal communication. He did not elaborate.

Camp 30, a medium and minimum security road-camp style facility with 160 inmates two miles from Fair Oak Mall, was the most escaped-from facility of its kind in the state during the past decade. Zimmerman said the other issues his office is investigating concern escapes.

Gov. Charles S. Robb last week ordered a complete review of security and management of the facility in response to complaints from Fairfax officials, but Zimmerman said his inquiry is independent of that review.

Fairfax County Prosecutor Robert F. Horan Jr. said yesterday he had requested guidance from the state attorney general's office about the building and said he would not act until Zimmerman's investigation is complete.

State corrections officials said last week they were surprised to learn of the building's existence.