Joseph Gatt, an actor with roles on “Game of Thrones” and “Star Trek Into Darkness,” has been arrested in Los Angeles on suspicion of engaging in “online sexually explicit communication with a minor.”Los Angeles police announced details of Gatt’s arrest in a news release Tuesday and issued an urgent plea for other potential victims to contact authorities.Gatt, 50, was taken into custody at his home in the Beverly Grove neighborhood on April 6, by detectives from the department’s Internet Crimes Against Children Task Force, the LAPD said. However, police did not release the information until this week.The LAPD said the arrest came after they received information that Gatt had allegedly communicated with a minor across state lines.