Photos and video footage from tourists who survived a fatal mid-air collision on Australia's Gold Coast will be key to the investigation into Monday's helicopter disaster that claimed four lives.
Footage aired by 7 News last night purports to show the moments before the helicopters collided from inside one of the aircraft.
The vision shows a passenger pointing out the window before tapping the helicopter pilot on the shoulder moments before grabbing the seat in front of them.
Police sources say the phones of passengers from the helicopter that was landed by pilot Michael James are now being examined as detectives and the Australian Transport Safety Bureau (ATSB) comb through hours of video footage sourced from witnesses, passengers and the aircraft involved in the tragic accident.
Investigators working to determine the cause of disaster spent Wednesday with the joy flights' operators.
A lipstick camera is a small camera that is mounted to different parts of the aircraft.
It is understood three lipstick cameras attached to the helicopter being flown by Ashley Jenkinson, which crashed into a sand bank, killing the pilot and three of his seven passengers, will be integral to working out what went wrong.
The cameras were being removed from the wreckages on Wednesday, but investigators are yet to determine what was captured in the helicopter's final moments before the collision.
Aviation expert Keith Tonkin said recovered photos and video footage taken by passengers may provide information that was not obvious from electronic data available from the helicopters.
"It might show where a pilot was looking, the weather conditions or some other information that's not immediately apparent that might assist to fill in a gap of information."
He said the cameras would have been either facing forward, looking out at the scenery or recording passengers from inside the aircraft.
"For tourist flights and sightseeing flights, they might have those lipstick cameras pointing at the passengers, so there's a record of the experience and how they appeared during that experience," he said.
"They may also be mounted in the helicopter to see what someone's doing for the purpose of training or examining them [pilots]."
Tonkin said they were commonly used in fighter aircraft to help pilots "debrief the flight".
Final crash report could take 'years'
Tonkin said while the ATSB's final report was expected be released within eight months, he tipped it could likely take longer.
"I have observed that some reports can take years to be published, so it might be a while yet before we find out the full details."
British couple Diane, 57, and Ronald Hughes, 65, were killed in the crash, alongside pilot Ashley Jenkinson, 40.
Vanessa Tadros, 36, was also killed in the crash and her 10-year-old son, Nicholas, remains in a critical condition.
Geelong woman Winnie de Silva, 33, and her son, Leon, 9, were also seriously injured.
De Silva is in a stable condition on the Gold Coast, while Leon remains critical at Queensland's Children's Hospital in Brisbane.
Tourists from New Zealand - couples Edward and Marle Swart, and Riaan and Elmarie Steenberg - were in the second helicopter.
They were taken to hospital without life-threatening injuries and are assisting the ATSB and police with their inquiries.