State police at Lehighton are investigating a statutory sexual assault incident in Monroe County.

Troopers said a 13-year-old female from Polk Township, was assaulted at a residence along Weir Lake Road, in Chestnuthill Township, during the period of Nov. 1 and 30, 2009. Troopers said a suspect had sex with the girl during that period.

Troopers said the suspect is known to them and the investigation is continuing.