POLICE have launched an investigation into claims a man was ordered to strip naked during a drug search in full view of bystanders as he picked up tickets for a Mardi Gras party.

It is the third internal NSW Police investigation into officers' conduct during the Sydney Mardi Gras festival.

Sydney creative director Gary Leeson, 55, said he was "humiliated" and "bullied" when NSW police ordered him to remove his pants and underpants during a drug search.

Mr Leeson was approached by a sniffer dog at 4.30pm on February 23, at the gates of the Sydney Mardi Gras Harbour Party in the Botanic Gardens, and taken by police into a covered enclosure for a full search.

He said he was patted down and repeatedly told he was lying when he said he did not possess any drugs. Then he claims police said: "Now drop your pants."

He alleges there was a gap in the tarpaulin covering the area and people walking past could see inside. "[They could see] my bare butt," he told news.com.au. "I was not comfortable with that at all.

"It's a complete abuse of their powers ... I feel embarrassed and humiliated."

Police refused to comment on specifics of the case, as it is now the subject of an internal investigation.

"As the investigation is ongoing it would be inappropriate to comment further," a spokeswoman said.

Police guidelines say strip searches have to be conducted in a private area, and away from the view of unnecessary people.

This comes a day after the NSW Police faced widespread community outrage over heavy-handed tactics after a video allegedly showed a teenage reveller being thrown to the ground by an officer last Saturday night. A second incident involving police on the same night is also being investigated.

Police were patrolling the gates of the Harbour Party, but Mr Leeson was not attending - just picking up complimentary tickets for friends at a booth near the gates.

"They use the excuse of a sniffer dog specifically so they can search you," Mr Leeson said.

Critics dispute the effectiveness of the dogs, saying they are often inaccurate.

But police strongly defend the accuracy of the canine detectors.

media_camera Whiff... Sniffer dogs have been controversial. Picture: Bob Finlayson

Acting Commander of the Dog Squad Mark Watters said more than 80 per cent of people pinpointed by drug dogs last year admitted carrying drugs, or having been in "contact" with them recently.

He said the Mardi Gras party has run for a number of years. "There has been drug seizures there in the past," he said, and there were 13 separate drug finds on the night.

Mr Leeson said that he understood police had to do their job, but believed it was excessive in this case.

"To pat you down, that's fine. But the removing of trousers and the implied threat that I was lying… There's no balance there. "

Drug educator Paul Dillon, who has worked at a number of events over the past 10 years since detector dogs were introduced, said there were consequences for breaking the law and using drugs.

"But do we really believe that police should have the power to subject innocent people to strip searches simply because a drug dog sits in front of them?" Mr Dillon asked. "Absolutely not."

Follow Daniel Piotrowski on Twitter: @drpiotrowski

Originally published as Man 'forced to strip naked' at Mardi Gras event