A helicopter pilot among four people killed in a midair collision had cocaine in his system but at a level unlikely to have affected his flying, a preliminary investigation has found.

The Australian Transport Safety Bureau on Tuesday released an interim report into the January 2, 2023, collision between two helicopters near Sea World on the Gold Coast.

The pilot of one aircraft was returning to a helipad with five passengers on board after a five-minute scenic flight.

A few minutes before 2pm a second tour helicopter took off with six passengers. It collided with the first aircraft, leading to an uncontrolled descent onto a sandbar that killed the pilot and three passengers and seriously injured three others.

The first aircraft was able to land with three people aboard suffering serious injuries and three with minor injuries.

The ATSB’s interim report was released to give an update on the investigation into the crash. It has made no formal findings as to the contributing factors.

An autopsy of the deceased pilot of the second helicopter, Ashley Jenkinson, found no evidence of significant disease but a toxicology report showed a positive result for cocaine.

The examining forensic pathologist reported no signs of chronic stimulant use and the cocaine was unlikely to have been consumed within 24 hours of the crash. It could have been taken up to four days prior.

Chief Commissioner Angus Mitchell said the pilot had a “low concentration” of cocaine in his system.

“It is unlikely there would have been impairment of the pilot’s psychomotor skills,” Mitchell said.

The ATSB has estimated its final report, which will include analysis, findings and any recommended safety actions, will be completed by September.

“This was a tragic accident, and it is our responsibility to make findings and drive safety actions, which reduce the likelihood of a similar occurrence in the future,” Mitchell said.

The interim report noted several steps that have already been taken by Sea World Helicopters, which is a separate business to the theme park, including greater air traffic control at the beachside heliport.

-AAP