Actor Josh Brolin poses on the red carpet during the premiere of "Deadpool 2" in Manhattan, New York. Reuters

Josh Brolin admits there is "no explaining" his domestic violence arrest and thinks it's only something his ex-wife Diane Lane should discuss.

The 50-year-old actor was charged with spousal battery and released after posting $20,000 bail in 2004 after then-wife Diane Lane claimed he'd hit her, but the case was later dropped and the pair stayed together before filing for divorce in 2013 and he believes only the 'Unfaithful' actress can speak out to clarify what happened.

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He said: "God, I've never been so careful with my words. Ever. Maybe in all 50 years. And there's no reason for me to be other than there's no explaining it. Do you know what I mean? The only person who can explain that would be Diane, and she's chosen not to, so I'm OK with that."

But the 'Deadpool 2' star - who has been sober for five years - admitted he has more "control" over his behaviour now, as things used to be much more "chaotic".

He said in an interview with the New York Times newspaper: "I was more reactive, I was more, 'People need to know the truth.' 

"Whatever I say [now] is going to sound like compensation for a perpetrator. I've gotten to a place where all that matters is that I have control over my behaviour, and at that time, it was a little more chaotic."

Josh - who has two children with first wife Alice Adair and is expecting a baby with current spouse Kathryn - tried to be a "hero" to Diane but eventually found it exhausting, which led to their problems, but he admits now he regrets not being "mature" enough to understand his feelings at the time.

He said: "I loved Diane. I loved being a father figure to her daughter. It just wasn't attainable, and in that hero mentality, you get exhausted, and then when you get exhausted, you get resentful, and then all that stuff comes out. 

"So I feel bad that I didn't have the presence of mind or the maturity or whatever to understand that early on.

After Josh's arrest, a publicist for the couple said the incident had been a "misunderstanding" and they were "embarrassed" it was taken so far.

Their representative said at the time: "There was a misunderstanding at their home. Diane called the police. Josh ended up being arrested for the lowest-end misdemeanor charge of domestic battery. 

"Diane did not want to press charges and asked them not to arrest him, but in cases involving the possibility of any physical contact, the police have to arrest first, ask questions later. 

They are home together and are embarrassed the matter went this far."

Diane declined to comment when contacted about the story.