Results from post mortem examinations will be a critical element to the police investigation into the deaths of a mother and her two children whose bodies were found in Yerrabi Pond in Gungahlin over the weekend.
The examinations will assist police in determining the cause of death for all three family members.
The bodies of two of the three members of the family - the mother and son - were first discovered in the murky pond around 8am by a passerby, who raised the alarm.
As the bodies were retrieved, grave fears were held for the safety of the second sibling, eight-year-old Pranav Vivekanandan, who was still missing.
The family car, a Subaru Forester, was parked close by where the two bodies were found, with the keys still in the ignition.
Police seized the car and took it to the Exhibit Management Centre in Mitchell for forensic examination.
ACT police issued a missing persons alert for Pranav Vivekanandan on Saturday afternoon, as his whereabouts were still unknown.
Meanwhile, the search of the extensive pond catchment by members of the Australian Federal Police dive team continued throughout Saturday afternoon and was only abandoned when fading light made it impossible for the drivers to continue.
Police maintained a cordon at the lake through the night and at first light, the divers returned to continue with their grid search pattern. Around 11am, they recovered the body of Pranav Vivekanandan.
Detectives have interviewed the father of the two boys but do not believe he had any involvement.
"At this stage, police do not believe any other party was involved," police said in a statement.
Police are preparing a brief for the Coroner, which will include the results of the three autopsies.
ACT police are expected to be able to provide a clearer picture of what they believe occurred, with the permission of the Coroner, once the results of the post-mortems are known.