CHESTER Delaware County detectives served a search warrant at the Chester Police Department Tuesday as part of an investigation into reported missing evidence, officials said.

The Delaware County District Attorney's office is conducting an investigation in response to a formal complaint about the department's evidence room, said spokeswoman Emily Harris.

The complaint and investigation are "in regard to missing evidence," said Summer Freeman, spokeswoman for Mayor John Linder.

Freeman said the search warrant is sealed, and city officials are cooperating with investigators.

Harris said she could not comment on whether any Chester police officers are under investigation. The district attorney's special investigations unit is handling the investigation.

A message left at the Chester Police Department was not immediately returned Tuesday evening.

- Laura McCrystal