Game of Thrones actor Joseph Gatt has been arrested on suspicion of "sexually explicit communication" with a minor online.
The Los Angeles Police Department said detectives executed a search warrant at his home at around 5am on April 6.
It said the juvenile division of its internet crimes against children task force had received information that Gatt, 50, "had been engaged in online sexually explicit communication with a minor across state lines".
The actor was arrested on an outstanding felony warrant over "contact with a minor for a sexual offence", the LAPD said.
Police said they were seeking to identify any additional victims following the arrest of Gatt, who plays Thenn Warg in the TV series.
The actor was released on $5,000 bail a few hours after his arrest, his booking report from the Los Angeles County Sheriff's Department showed.
In an Instagram statement posted on Wednesday, Gatt called the allegations "100 per cent categorically wrong and reckless".
"I have confirmed errors and misleading information in today's press release," he wrote.
"I am fully co-operating with police and LAPD to get to the bottom of this. I look forward to clearing my good name."
The LAPD's task force comprises more than 100 agencies investigating child predators who use the Internet to contact children or look at child sexual abuse material.