A Southern California high school teacher was arrested on unlawful sex charges two weeks after she gave birth to a baby that was allegedly fathered by a student, Redlands police said Tuesday.

Laura Elizabeth Whitehurst, 28, was arrested Monday night for allegedly having unlawful sex with a 16-year-old, Redlands police spokesman Carl Baker. She was the boy's adviser.

Officials at Citrus Valley High School in Redlands contacted police on Monday, acting on a tip from the boy's mother.

The sexual relationship began last summer and continued for nearly a year, police said. The boy is now 17.

Whitehurst gave birth to the child June 18.

A telephone message left at the Whitehurst home was not immediately returned.

In a statement, Redlands Unified School District Assistant Superintendent Sabine Robertson-Phillips said they were "recently made aware of allegations involving a high school student and teacher."

Police were immediately notified and Whitehurst was placed on leave, Robertson-Phillips said.