Bone fragments of missing campers shown to jury

A trial has been told about bone fragments belonging to Russell Hill and Carol Clay being found. (HANDOUT/VICTORIA POLICE)

Bone fragments belonging to Russell Hill and Carol Clay were discovered in remote bushland more than 18 months after they disappeared, a jury has been told. 

Dozens of photos of bones, teeth and watch parts uncovered by detectives were shown in the Supreme Court in Melbourne on Thursday.

Airline pilot Greg Lynn is on trial accused of the double murder of Mr Hill and Mrs Clay in March 2020 while they were camping in Victoria's Wonnangatta Valley, and burning their remains in the bush.

The 57-year-old has pleaded not guilty to both counts of murder.

Bone fragments from Bucks Camp belonged to Mrs Clay, the jury heard. (Supplied/AAP PHOTOS)

Forensic officer George Xydias told the jury he assessed an area of bushland near the Union Spur Track, east of Wonnangatta, between November 29 and December 1, 2021.

He was part of a crew that carried out line searches and eventually used heavy machinery to excavate a section that was blackened by fire, he said.

A fallen tree trunk 16m away was also analysed and bone fragments along with three teeth and parts of an old wrist watch were located, Mr Xydias told the jury.

The expert said a fire had been lit on the cleared section of land and the bones and other burnt items were thrown into the open tree trunk.

Dr Dadna Hartman, from the Victorian Institute of Forensic Medicine, confirmed at least one of the bone fragments found at Union Spur Track belonged to Mr Hill.

She told the jury she also carried out testing of bones fragments at Bucks Camp, where the murders allegedly occurred.

The fragments, found by detectives in March 2022, belonged to Mrs Clay, Dr Hartman told the jury.

Dozens of photos of bones, teeth and watch parts uncovered by detectives were shown to the jury. (Supplied/AAP PHOTOS)

It's alleged Mr Hill and Mrs Clay died on March 20 after an argument between Lynn and Mr Hill at Bucks Camp.

Mr Hill had threatened to send his drone footage of Lynn deer hunting near the camp to police, defence barrister Dermot Dann told the jury.

He said a scuffle broke out after Mr Hill took a gun from Lynn's vehicle and Mrs Clay was accidentally shot by Mr Hill.

The barrister said Mr Hill came at Lynn with a knife and was accidentally stabbed in the chest as Lynn defended himself.

However, prosecutors allege Lynn intentionally killed Mr Hill and Mrs Clay.

Lynn burned Mrs Clay and Mr Hill's campsite, put their bodies in his trailer and dumped them.

The trial continues.