Police listened to more than 5000 covert recordings of Greg Lynn in his home, car and campsites to build the case against the former airline pilot accused of killing campers Russell Hill and Carol Clay.
It's alleged the 56-year-old made comments about the deaths of the campers, which were picked up on the secret listening devices and led to his arrest in November 2021.
Mr Hill and Ms Clay vanished while camping in the Wonnangatta area of Victoria's alpine region in March 2020.
