Authorities on California's Central Coast confirmed that a swimmer who went missing in Monterey Bay last month died from a shark attack.

On Thursday, the Santa Cruz County Sheriff's Office revealed the cause of death of Erica Fox. The 55-year-old went missing while swimming with a group off Lovers Point in Pacific Grove on Dec. 21.

According to deputies, the coroner determined the cause of Fox's death to be "sharp and blunt force injuries and submersion in water due to a shark attack". The coroner said the manner of death has been ruled an accident.

"The Sheriff's Office once again extends its deepest condolences to Erica Fox's family and friends during this difficult time," the agency said on social media.

Witnesses reported seeing a splash before Fox disappeared, and investigators said people in the area reported seeing a shark.

Authorities conducted more than 15 hours of search operations, covering more than 84 square nautical miles, before suspending the search the following day.

The woman's body was recovered on Dec. 27 by Santa Cruz County deputies about four miles south of the community of Davenport, about 25 miles from where she went missing.

Fox was the co-founder of the "Kelp Krawlers", an open water swimming group.