Hash cookies prove no memory lost: PIC

An ex-NSW cop who allegedly lied to the police watchdog about taking drugs with other officers couldn't have had a memory blackout because he remembers eating hash cookies, a court heard.

Former detective inspector Shane Diehm fronted Sydney's Downing Centre Local Court on Monday charged with four counts of providing false or misleading information to the Police Integrity Commission (PIC) in relation to Operation Ischia.

The operation was established to investigate allegations former and serving police used and supplied drugs and released confidential information.

Video played in the court showed Diehm and four or five other men, some also police, drinking and joking in a Gold Coast unit in 2010.

The prosecution alleges Diehm and his friends were taking ecstasy tablets and eating hash cookies.

The former Tweed police crime manager told the PIC during its earlier investigation he ate some hash cookies and took a tablet without knowing if it was an illicit drug.

Diehm had told the PIC he couldn't remember who else was taking drugs, because he suffered depression and regularly drank heavily, the court heard through his psychiatrist Dr Olaf Nielssen.

Dr Nielssen said Diehm may have lied to the PIC because of the anxiety caused and exacerbated by his drinking.

"It affected his performance more so than it may have a person without his condition," he told the court.

"You are afraid of what the consequences might be."

But when pressed by the prosecution, Dr Nielssen conceded that Diehm couldn't have suffered a total memory blackout because he remembered eating hash cookies.

Diehm and two other officers tested positive for cocaine after the Sydney retirement party of a colleague in August 2011.

The hearing continues.