The mother of a 19-year-old soldier who committed suicide after allegedly enduring racial abuse from a Defence instructor is expected to tell her story to a Senate committee hearing in Canberra today.

The Chief of the Defence Force, General Peter Cosgrove and the heads of the Army, Navy and Air Force will also appear before the committee's first public hearing.

The committee is examining a number of peacetime deaths in the military, including that of 19-year-old Damien Palmer.

His mother, Donna, wrote to the committee complaining that her son was singled out for being an Aborigine and subjected to racist comments before he committed suicide.

In another submission, it is claimed a survivor of the HMAS Westralia fire six years ago killed himself after being sent back to the ship while still suffering severe shock over the death of a friend.

The committee will put the allegations today to General Cosgrove and his most senior officers.

More families are expected to give evidence next month and the committee will report in May.