Russell Crowe was led from the police station to court in handcuffs

The incident in New York in the early hours of Monday was "possibly the most shameful situation I've ever gotten myself in in my life", he said.

"And I've done some pretty dumb things in my life. So to actually make a new number one is spectacularly stupid."

The Oscar-winning actor, who has been charged with assault, told US TV host David Letterman he was extremely sorry.

Mr Crowe confronted porter Nestor Estrada about a faulty phone system in the Mercer Hotel.

I'm at the bottom of a well - I can't communicate how dark my life is right now Russell Crowe Watch his apology

The star's publicist has said the phone hit the wall, but police said it struck the employee in the face.

"Hopefully at some stage, I'll be able to apologise directly to Nestor," Mr Crowe said.

"But at the moment, he's not answering his phone."

Being a husband and father away from home was "a level of abject loneliness that I'm not used to at all", the actor added.

He told Australian newspaper The Daily Telegraph: "I'm at the bottom of a well. I can't communicate how dark my life is right now."

Mr Crowe blamed the outburst on a whistlestop trip to the UK, a few drinks and not being able to call wife Danielle and son Charles in Sydney.

He spent the weekend in Manchester supporting Australian boxer Kostya Tszyu in his bout against Ricky Hatton.

Russell Crowe plays a boxer in his new film, Cinderella Man

"But I've got no excuses," he told the paper. "There's nothing you can say to people to explain the combination of jet lag, loneliness, and adrenalin.

"I know it's my fault. I've got to face up to it and deal with it. I'll cop whatever I cop."

Mr Crowe spent several hours in jail before being taken out in handcuffs in front of the media to court on Monday.

He has been charged with second degree assault and possession of a weapon, the phone, and must return to court in September.