KEY WEST, Fla. -

A Florida Keys man was arrested on a charge of incest after he impregnated a relative, a Monroe County Sheriff's Office spokeswoman said.

Brandon Williams, 31, was arrested on the third-degree felony charge Monday.

Monroe County Sheriff's Office spokeswoman Becky Herrin said detectives discovered Williams repeatedly had sex with a teenage relative and had a child with her as a result.

Williams also faces a second-degree felony charge of underage sexual assault.

The identity of the relative was not released because of her age.