An employee at State College Medical Services, 477 E. Beaver Ave., received a suspicious letter containing a white powdery substance on Monday. The State College Police Department sent the substance to the State Health laboratory to investigate the contents of the envelope, police said.

Police Sgt. Dana Leonard said the results of the substance remain unknown. The results generally take three to four days to process, Leonard said.

The clinic will remain closed until results from the laboratory come in, police said.