Authorities are continuing a major investigation at a Northern California animal rescue, where excavations for a third day have uncovered dozens of animal remains and left more than 700 shelter dogs unaccounted for.

The probe in Humboldt County involves the Humboldt County Sheriff's Office, the Federal Bureau of Investigation, and state agencies. It began after a burial pit containing eight dogs with apparent gunshot wounds was discovered on the property.

Investigators say dozens of additional remains have since been recovered, many with microchips. The rescue, which received dogs from shelters including those in Berkeley and Oakland, remains open and no charges have been filed.

Officials say the investigation is ongoing and could involve potential animal cruelty, fraud, and other violations. The owner denies wrongdoing.

abc7news.com