Assistant Commissioner Robert Hill was part of the taskforce that descended on Chapel Street until 5am on Sunday using sniffer dogs to inspect patrons for drugs as they waited to enter venues.

No searches were conducted inside licensed premises, although door-staff at one venue were inspected by sniffer dogs.

Superintendent Philip Green said the number of people caught with drugs was "disturbing".

"If there are clubs out there doing the wrong thing, if there are clubs out there who are remaining blind to or encouraging drug use then they will prosecuted with every tool available to Victoria Police," he said.

"We will prosecute as long and as hard as we can."

Drugs seized during the operation included cannabis, amphetamine, cocaine, ketamine??? and MDMA.

But several venue owners claimed police were focusing on "low-hanging fruit", when scarce law enforcement resources should be focused on the crime gangs responsible for the production and trafficking of drugs.

"It was completely over the top and they didn't actually catch anyone dealing," said a South Yarra club manager who asked not to be named.

"This was just window dressing for you guys in the media."

Another venue owner accused the police of breaching an agreement to co-operate with owners and operators following two drug-related deaths in the Chapel Street precinct between January 13 and January 15.

At a January 24 meeting of the Stonnington Liquor Forum attended by Assistant Commissioner Hill and Superintendent Green, police said they wanted to develop strategies in consultation with venues rather than pushing something on them.

Notes from the meeting reveal police claimed "better outcomes can be achieved by working in partnership, not just enforcement".

The relationship between police and venue operators was further strained in February, when the contents of the deadly batch of drugs responsible for a spate of overdoses was uncovered but the findings were not released.

An internal police memo marked "not for public release" warned officers that capsules sold as MDMA "actually contains a cocktail of illicit substances."

The nightclub industry claims information about the drugs would have assisted in their attempts to curb drug use and overdoses in venues.

Superintendent Green said Operation Safenight would run until August in conjunction with other specialist police resources including the dog squad and Taskforce Razon, which investigates licensed premises, and the transit safety division of the highway patrol.

"Our focus is on safety and harm prevention. We're not here to arrest our way out of community problems."