"I have spoken with the owner of the business and I think they're taking measures to resolve that at their end."
Young Nats president Sam Stead rejected Mitchell's claim.
"This issue has nothing to do with us. The Young Nats wouldn't waste their time on an MP they've never heard of."
Security guard John Domoney, who was working at the bar at the time, told Newshub that Mitchell and his friend were asked repeatedly to move from an area where bar staff needed to pass through.
Domoney said that when they were asked to move, the bar staff were told: "We are the law."
He said that Mitchell accidentally hit a female bar staffer on the side of a head with a glass.
"A female staff member came out of the bar crying and upset and she had said one of the guys from that group which was Clayton had hit her on the side of the head with a glass and spilled his drink on her," he told Newshub.
"It wasn't an assault, it was more of an accidental incident, but it was because he was in that bar area."
But Mitchell said he and his friend were ordering a drink at the bar, and there was plenty of room for bar staff to move around them.
"If standing at a bar that is busy and ordering a drink is being a 'dick', then I think that's why they need to talk to the security member about their behaviour."
He said he and his friend moved away from the bar after getting their drinks, and security approached them three minutes later.
He said he told security he would make a phone call, and was then grabbed and removed.
"I was actually on the phone to the owner at the time while trying to resolve this issue when I was grabbed quite forcefully by these buffoons.
"There was no fighting. We were just trying to go out quietly and calmly but there was a bit of a kerfuffle and I would say a huge overreaction on behalf of security."
Asked if he owed anyone an apology, Mitchell said that he was the one who should be given an apology.
New Zealand First Winston Peters said that there was video footage exonerating Mitchell, but he had not seen it himself.
"We are so happy for you to see it that we ask you to turn up on Saturday night, have a good hard look at it, and then tell the public what you think," Peters told reporters.
"If you can't justify it with evidence, stop speculating."
Asked about the accidental contact with the female staffer, Peters said: "You're just scaremongering and making it up as you go along. Why don't you look at the video? That exonerates Mr Mitchell totally."
Peters said he had not seen the video, but he had been told what was on it by someone he had "enormous trust" in.
