The pair had spent Monday afternoon at an Oscars party at the Pullman Hotel.
Graves was arrested and spent the night behind bars until he appeared in the Auckland District Court yesterday and was remanded on bail.
Graves said they had split following his arrest and doubted they had a future together.
In March last year, Castle-Hughes was taken away in handcuffs from a central Auckland nightclub following a fight. Graves reportedly came to the defence of his girlfriend when another patron made a derogatory remark about her.
An Auckland Alcoholics Anonymous member, who wanted to be known only as William, urged Castle-Hughes to return to meetings.
"It's not a programme that you can start and stop."
He said it would be hard for Castle-Hughes to be in a relationship with someone who drank.
"At Alcoholics Anonymous we do say don't get into a relationship in the first two years because your emotions are too mixed up," he said.
Clinical director of Alcohol and Drug Assessment and Counselling Roger Brooking said Castle-Hughes seemed to meet the criteria of an alcohol abuser.
"If you get assaulted when you are drunk that is a reasonable indication that your drinking had something to do with it. When somebody is appearing in the media with problems happening while they are drunk they clearly need to get some help," he said.
Castle-Hughes' former manager, Graham Dunster, said he supported her.
"I enjoyed working with her. She was a great kid. Actors are human beings too. They are individuals who are in the spotlight and that's not always easy. You can't judge someone for their circumstances," he said.
He believed Castle-Hughes still had a great career ahead of her.
Castle-Hughes' former partner Bradley Hull said he was no longer a part of Castle-Hughes' personal life.
In 2010, Castle-Hughes split with Hull, the father of her 4-year-old daughter Felicity-Amore, after the couple had spent seven years together.
"I choose not to get involved. My job is to look after Felicity," he said.
Neither Castle-Hughes nor her agent could be reached for comment.