The Maryland state prosecutor has launched a preliminary investigation to determine whether criminal activity took place during Montgomery County's supervision of the planning of Clarksburg Town Center, according to county officials.

Derick Berlage, chairman of the Montgomery County Planning Board, released a brief statement yesterday saying his office had been contacted by prosecutors.

"An inquiry has been initiated, a preliminary inquiry, and we have been made aware of it," Berlage said in an interview. "We intend to cooperate fully."

In his written statement, he said: "We have seen absolutely no evidence whatsoever of criminal wrongdoing. . . . But, we welcome an outsider who will take a comprehensive look and make an independent determination."

State Prosecutor Robert A. Rohrbaugh did not return calls yesterday. But Wednesday, he declined to comment on the matter, saying it is his policy not to comment on possible investigations.

A county official, who asked not to be identified because of the ongoing investigation, said prosecutors are interested in knowing why a senior planner altered a legally binding site plan before a Planning Board hearing in April.

The planner, Wynn Witthans, declined to comment yesterday. A spokesman for Newland Communities, the developer of Clarksburg Town Center, pledged the company's cooperation.

The controversy was sparked last month by a group of Clarksburg residents, who spent many hours investigating how their northern Montgomery community was being constructed. Last fall, the group began to suspect that hundreds of townhouses in the neighborhood were built too high.

They contacted council member Michael Knapp (D-Upcounty), who asked Berlage to investigate. Berlage, who said he was relying on information from the staff, replied in an e-mail that there were no height violations. But residents appealed the case to the full Planning Board, which scheduled a hearing on the matter for April.

The site plan data table for Clarksburg Town Center, which is a legally binding construction blueprint, states that townhouses in the neighborhood cannot be taller than 35 feet.

Before the April hearing, Witthans produced a site plan that had "four stories" written on it in black marker. The developer, Newland Communities, had been arguing that it was allowed to build townhouses as tall as four stories or 45 feet. Based on Witthans's testimony, the board ruled 4 to 1 that there were no height violations.

A few weeks later, a Clarksburg resident uncovered an original site plan, which stated that height limits were 35 feet.

The Planning Board, after acknowledging that Witthans had altered the document, scheduled another hearing. Last week, it ruled that 433 townhouses were built too tall and 102 houses were built too close to the street.

In an interview last week with The Washington Post, Witthans said she was merely trying to bring the site plan into conformity with earlier board opinions and the staff report. She said that was a mistake brought on by her heavy workload -- a claim county officials do not deny.

The county Office of Legislative Oversight and Thomas Dagely, the inspector general, have launched separate probes into the matter.

"There is obviously a cloud, and we need to have every relevant government agency take a look so we can get to the bottom of it," said Council President Tom Perez (D-Silver Spring).

Council member Steven A. Silverman (D-At Large) suggested that the state investigation could be politically motivated, saying he was "baffled as to why Rohrbaugh would stick his hands in it" and noting that Rohrbaugh was appointed by Gov. Robert L. Ehrlich Jr. (R).