The 15-year-old claims he "froze" when he was asked to drop his pants during a strip-search at Sydney Olympic Park in February.

The teenager says an officer told him to "hold your dick and lift your balls up and show me your gooch".

But a senior constable named on an official form as one-of-two officers involved in the search can't remember performing any strip-searches at the Lost City festival.

He told a hearing of the Law Enforcement Conduct Commission on Wednesday that he'd recall if such language was used.

"I have no memory of that happening," the senior constable said.

The police officer of six years - who can't be named - said he was familiar with the term "gooch" and may have used it in his school days but would not have done so in his time with NSW Police.

Asked if having no memory of the event meant it didn't happen, or that it could've happened but he'd forgotten, he said: "I would say that it didn't happen."

The officer's handwriting appears on a form in relation to the teenager which notes that a general search was carried out.

He admitted it was an "error" to circle "no" for signs of intoxication despite noting on the paperwork that the teen had enlarged pupils and was shaking.

But he said he wouldn't have made those notes if they weren't true.

The teenager - on whom no drugs were found - has told the commission in a statement he was confused as to why he was stopped after a drug dog sniffed him but did not sit down - which he thought needed to happen to indicate a drug detection.

The boy said he was so nervous he was shaking.

The officer on Wednesday accepted the teen's pupils could have become larger when he moved from the bright light outside to the darkened search area.

LECC chief commissioner Michael Adams QC said it was "not rocket science" to suggest the shaking could have been due to nerves rather than drug-taking.

Mr Adams questioned why a teenage boy would be allowed to go back into a festival "awash with drugs" if police had recorded on a form that he appeared to be affected by drugs.

"What about your duty of care?" Mr Adams asked.

Questioned as to whether he thought that was a responsible thing to do, the officer replied: "That looks to be a mistake on my part."

He agreed when Mr Adams suggested further training for officers might be required on strip-searching young people and on detecting the signs for when a person might have taken MDMA.

The party drug was found in nine searches carried out at the festival which was attended by some 10,000 young people.

The second officer named on the form for the search of the boy said he "definitely" wouldn't have used the term "gooch" and that he had only been involved in one general search that day, as opposed to a strip-search.

"To be honest I don't know what it (gooch) actually means," he told the inquiry.

The week-long hearing is considering the 15-year-old boy's case alongside two other teenagers, as well as the lawfulness and reasonableness of strip-search practices generally.

Australian Associated Press