Arnold Berdon, the husband of UFC flyweight Rachael Ostovich, was arrested on suspicion of second-degree attempted murder.
Berdon, who turned himself into Honolulu police late Tuesday, has not been formally charged with a crime but remained in police custody as of Wednesday evening.
Ostovich, 27, was hospitalized last weekend with a broken orbital bone, according to her manager, Brian Butler-Au. She was granted a restraining order against Berdon, 27, on Monday. That order expires in May 2019.
Berdon is also a professional MMA fighter, with a 7-2 overall record. He has fought on various regional shows, including Titan FC and Victory FC.
Ostovich was scheduled to face Paige VanZant at UFC Fight Night on Jan. 19 in Brooklyn, but was forced to withdraw due to the injuries suffered last weekend.
She has not publicly commented on the alleged attack but posted a message on her Instagram account Tuesday that read, "Spend time praying for people instead of talking about them."