WEST COVINA (CBS) — Magnetic tape containing Social Security numbers, medical information, investigative reports and other data mailed from a state Department of Public Health office in West Covina was missing Wednesday.

The tape included information on as many as 2,550 people, state Department of Public Health employees and health care workers, and the data as not encrypted, a department spokesman said.

Someone at the state Department of Public Health office in West Covina mailed the tape to a central office in Sacramento to be backed up but, when the envelope arrived Sept. 27, it was unsealed and empty.

The agency is notifying each person affected and offering advice on how to guard against identity theft, according to the state. It took until Nov. 23 for a list of affected people to be compiled.

So far, there is no evidence the information has been used illegally, a spokesman for the Public Health Department said.

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