Christchurch Casino's CEO is standing behind his three security staff after their handling of a drunk man.

Footage has emerged of the man being being pushed to the ground, where his head was in gutter water for around 10 seconds.

The man was reportedly thrown out of Mashina Lounge on February 15 and subdued twice after attacking security and harassing a woman.

Brett Anderson says the handling of the situation was untidy but there's no need to take the action any further.

"No, there is no reason for any disciplinary action.

"I mean we constantly review how we do things and take learnings from it but they were responding to a threat to them and other patrons.

"It wasn't intentional that it ended up in the gutter.

"That was circumstance in terms of level of aggression being displayed."