Matt Christopher Lockley, 28, tells court he knocked on wrong door amid panic attack on flight from Brisbane to Denpasar

man who sparked a hijack scare on a flight to Bali says he felt disoriented and sick when he mistakenly knocked on the cockpit door, believing it led to the toilet.

Matt Christopher Lockley, 28, pleaded not guilty on Thursday to interfering with crew members on a Virgin Australia flight from Brisbane to Denpasar last April.

Flight crew triggered an “unlawful interference” alarm when the plumber from northern New South Wales allegedly tried to enter the flight deck.

The alarm placed Indonesian military on alert for a hijacker.

Lockley told his Brisbane trial he had suffered a panic attack several hours into the flight and had needed to go to the toilet.

“I felt like I was going to faint, felt like I was going to throw up,” he told the Brisbane magistrates court.

“I felt totally disoriented and what I thought was the toilet door later I’ve found out to be the cockpit door.”

Lockley said he was not drunk or under the influence of drugs but a passenger who helped subdue him said the plumber had confided he’d been “doing drugs” in the past week.

Businessman Stephen McDonald testified that a remorseful Lockley told him he had been trying to talk to the pilots about “getting medication from his bag”.

The court heard Lockley had been behaving strangely beforehand and had asked flight attendants to throw away some vitamin bottles he had because he suspected they had been tampered with by other passengers.

At the same time flight attendants were dealing with Lockley, a passenger suffered a suspected heart attack.

Flight attendant Jenni Manning said she was forced to break protocol and leave the semi-conscious patient alone briefly to get oxygen as there was no other cabin crew free.

Soon after the medical emergency, Lockley was seen pounding on the cockpit door, rattling the handle and yelling “let me in”, the court heard.

Feeling threatened, flight attendant Angela Demo dialled the cockpit and uttered a coded phrase that signalled a hijack or unlawful interference, which prompted pilots to alert air traffic control.

“I was frightened,” she said.

“He seemed aggressive towards the flight deck door.”

Pilot Neil Cooper said he had heard the loud noises but was nt aware of the exact situation when he raised the alarm.

“We have protocols in place and … if that phrase is used we follow those drills,” he said.

On landing, Indonesian military and police boarded the flight and escorted Lockley off in handcuffs.

He was held for questioning but released without charge three days later and sent back to Australia.

Magistrate Judy Daly is due to deliver her verdict at 9.30am (AEST) on Friday.