The Montgomery County Department of Park and Planning isn't cooperating with an investigation into the agency's oversight of Clarksburg Town Center, the county's inspector general reported this week.

Inspector General Thomas J. Dagley said the agency, which makes recommendations on land-use policy to the county Planning Board, is withholding information and dragging its feet on requests to interview staff members.

In a letter to County Attorney Charles W. Thompson Jr. dated Monday, Dagley said he is looking into at least two other matters involving the agency, although he would not say what they are.

"Currently, failure of the Department to provide the requested information within a reasonable time is adversely affecting at least three inspector general projects," Dagley wrote.

Dagley told Thompson that he may issue subpoenas if the planning department does not comply.

The inspector general launched a fraud investigation this summer after it was discovered that hundreds of homes in Clarksburg were built too tall or too close to the street. In June, a senior planner resigned after it was discovered that she altered a site plan.

Dagley's probe is one of several, including an inquiry by the Maryland state prosecutor, into the agency's oversight and enforcement of standards in Clarksburg.

The Office of Legislative Oversight, the investigative arm of the County Council, is completing its inquiry. Patrick Lacefield, a council spokesman, said five members of the Planning Board have refused to be interviewed.

Planning Board Chairman Derick P. Berlage, who has pledged that the agency will cooperate fully, said yesterday that commissioners are barred by law from speaking about Clarksburg because the matter is before the board.

As for Dagley's letter, Berlage disputed its premise, saying the agency has provided much of what the inspector general requested. "He will get all the information he has requested, and we will provide that as quickly as possible," he said.

Several council members expressed alarm yesterday over the contents of Dagley's letter, saying it undermines the investigation into Clarksburg and could further erode public confidence in the planning process.

"It is unbelievable they haven't complied. It is totally unacceptable," said County Council member Nancy Floreen (D-At Large).

Dagley said the agency has missed several deadlines to comply with his requests for information on county-funded "expenditures and vehicles."

The agency did turn over "some preliminary" data Oct. 18, more than a month after it was due, Dagley said.

He said the submission "is not complete," and other information due Oct. 7 had not arrived. Also, he has interviewed only one of several planning staff members he wants to talk to, according to the letter.