COSTA MESA, Calif. (KABC) -- A deputy with the Los Angeles County Sheriff's Department was arrested on suspicion of performing sexual acts with a 13-year-old girl.The sheriff's department said it assisted the Costa Mesa Police Department with the arrest of 26-year-old Jovanni Argueta in Whittier on Wednesday.Costa Mesa police said they were called by staff from Costa Mesa Middle School on the morning of Oct. 22, regarding a suspicious man seen on campus.The man was later identified as Argueta and he left the campus before officers arrived, police said.Detectives said it was learned Argueta and a 13-year-old student from the middle school originally met online a year earlier through an online fantasy computer game.Over the course of the year, when the girl was 12-years-old, Argueta met with her on numerous occasions, according to police.Detectives said Argueta reportedly performed sexual acts with the girl and would meet her both on campus and away from school.The sheriff's department said Argueta was immediately relieved of duty pending the outcome of his case.Argueta was hired as a deputy in August of 2014 and was working at a local men's jail.In a statement, the sheriff's department said in-part, "The Los Angeles County Sheriff's Department expects all of its members to hold themselves to the highest ethical and professional standards at all times. Allegations of this magnitude are disturbing and disappointing."Argueta has been charged with child molestation and child annoyance. He posted bond on Thursday and was released from jail.