Cingular Wireless filed a lawsuit Friday against Charles Kelly, one of five private investigators who allegedly impersonated Hewlett-Packard Co. board members in an effort to obtain customer calling information.

The case, filed in the U.S. District Court for the Northern District of Georgia, is seeking to get Kelly and his firm, Georgia-based CAS Agency Inc., along with any of its agents, to return confidential caller information and any profits made from the obtained data. The suit asks for an injunction from the court to prevent Kelly and his firm from obtaining any further customer information. It also claims punitive damages.