PITTSBURGH — The former controller of a Marcellus Shale natural gas drilling firm has been charged in an ongoing federal investigation of more than $5.4 million allegedly embezzled from the Western Pennsylvania business.

The owner of Falcon Drilling LLC in Indiana, Pa., says he wants to review the criminal charges against his former employee before commenting. She’s identified in court papers filed today as Cheryl Diane Brooks. Her defense attorney did not immediately return a call for comment.

In February, the chief operating officer of the company, 52-year-old Larry Winckler of Indiana, was charged by state police with embezzling nearly $1 million.

The state police charged Winckler based on information provided by Brooks, who was not charged then. The state charges against Winckler were dropped so federal prosecutors could take over the case.