A prominent Vancouver nightclub owner says safety concerns drove him to send private investigators into a city-licensed party to expose alleged drug use, overcrowding and over-serving.

Last month, Bijan Ahmadian, who runs the Odyssey nightclub, hired undercover sleuths to attend a Halloween event put on by Vancouver Arts and Leisure, a self-described radical artist-run group.

Ahmadian told CTV News that rumours about what was going on at VAL events left him worried about attendees’ safety.

“We sent two private investigators to verify the stories we’d heard – grave concerns from some of our artists and some of our customers about safety issues,” Ahmadian.

“As it turned out, a lot of that was true.”

What the investigators found, according to their report, was people using cocaine and having sex while bartenders over-served alcohol. One sleuth said he was able to purchase a four-shot drink for $30, following a brief moment of apprehension from his bartender.

The most troubling allegation was that the venue, a Main Street warehouse licensed to hold 150 people, was packed with nearly 500 partiers and staff.

“As soon as you have a large group of people involved in alcohol and drug use in a very small and confined space, panic can spread very quickly, and that can be catastrophic,” said DIG investigator Tom Dolo.

The investigators also recorded people apparently smoking indoors, fueling fears about what could happen in such a crowded party if a fire were to break out. Last month, a nightclub blaze in Bucharest killed 60 people – a story that mirrors others in the U.S. and elsewhere.

Police arrived to check on the party at 3 a.m., but the investigators said guests had just piled onto a bus and left for an after-hours event at an auto shop on Clark Drive.

The VAL party, called Backdoor Vancouver, was billed as a way to profile local artists. Planner Matt Troy slammed the undercover probe, which recorded partiers on hidden cameras, as an invasive and political attack “on the morality of gay men, queer spaces, and queer events.”

“We reject these attacks on Vancouver culture, but we always welcome the discussion of the important issues facing artist-run spaces and artistic vitality in the city,” Troy wrote in a statement.

Troy would not comment on the specific allegations, but denied many of the investigators’ findings in a report in The Province newspaper.

Ahmadian told CTV News he’s not concerned about the alleged sex going on at the party, and there is no law against sexual contact at private events in B.C.

He also insisted the probe wasn’t intended to hurt his potential competitors, and that he wants Troy and the VAL to continue planning events – provided the governments takes a more hands-on approach to ensuring regulations are followed.

“But we’re hoping that police… the liquor branch and the city will pay particular attention to this and make sure it’s done in a safe way,” he said.

Ahmadian said he initially relayed concerns about the event to liquor inspectors, but after they didn’t follow up he felt obligated to launch a private investigation. On Tuesday, the B.C. Liquor Control and Licensing Branch confirmed it is probing last month’s party as a complaint.

“Clearly we have rules that need to be followed and liquor licensing and control have their responsibility to enforce,” said John Yap, parliamentary secretary for liquor reform.

With a report from CTV Vancouver’s Jon Woodward