CCTV shows Melbourne police enter swingers club before shooting 'The Joker and Harley Quinn'

CCTV footage has emerged showing heavily armed police entering a Melbourne nightclub moments before shooting a couple at a swingers party.

Police received reports a man, dressed as Batman's nemesis The Joker, was carrying a gun at the saints and sinners party inside Inflation.

After making their way inside in the video obtained by Fairfax Media, the Critical Incident Response Team officers reportedly opened fire just seven seconds after confronting the couple, who were engaged in a sex act on a couch.

The man wielding the fake gun as part of his Joker costume was shot in the torso, while the woman dressed as The Joker’s psychotic sidekick Harley Quinn was shot in the leg.

The injuries were not life threatening.

The victims have since been identified as 35-year-old man Dale Ewins and local government facility co-ordinator Zita Sukys.

A photograph has raised new questions about a police shooting in a nightclub. Source: 7 News

Partygoers dance at the saints and sinners swingers party at Melbourne nightclub Inflation.

Security told police the gun was a toy or fake weapon rather than a real one but when officers approached the man he allegedly drew the gun from his pants and would not drop it when asked.

The club's owner Martha Tsamis said the man wasn't holding a gun and was in a "compromising position" with the woman when police "stormed in" and opened fire.

"I wonder if I could have done more on the night to protect my staff and patrons," she said.

"All I want now is for this to be properly investigated and for the truth to come out. This has traumatised everyone associated with the business.

The Independent Broad-based Anti-corruption Commission said it would now be examining the shooting.

Police entered the nightclub after reports a man dressed as the Joker was carrying a gun.

The probe will consider information given by nightclub staff, initial police reports, witness statements and CCTV footage.

"In assessing the matter, IBAC will oversight Victoria Police's investigation being conducted by the Armed Crime Squad and Professional Standards Command and determine further action required," IBAC said in a statement.

IBAC commissioner Stephen O'Bryan QC said he had spoken to Victoria Police Acting Chief Commissioner Shane Patton about the matter.

The police shootout happened at Melbourne's inflation nightclub on Saturday morning. Photo: 7 news

Police shot a man dressed as the Joker and a woman dressed as Harley Quinn. Photo: 7 News

The nightclub last week lodged a complaint against police over a drug search at the nightclub, unrelated to the latest incident.

IBAC has confirmed with Victoria Police that arrangements are in place to deal with any "potential or perceived conflicts of interest" in the initial police investigation, "including as a result of recent civil action taken by the owner of the nightclub".

Victoria Police said it will provide "complete assistance to IBAC with its examination".