Private Sean Benton and Private Cheryl James died of bullet wounds in separate incidents while on guard duty.
The army said both committed suicide but an inquest into Private James's death instead recorded an open verdict.
The Deepcut death toll
Private Sean Benton, died June 1995, gunshot wounds to the hest
Private Cheryl James, died November 1995, bullet through her forehead
Private Geoff Gray, died September 2001, two gunshot wounds to the head
Private James Collinson, died March 2002, single gunshot wound
And it has emerged that an investigation is already under way into the deaths of two other soldiers in similar circumstances at the barracks.
Both those were also put down to suicide.
Doreen and Des James of Llangollen, north Wales, now say they have heard allegations their daughter Cheryl suffered a culture of sexual harassment and violence at the Princess Royal Barracks.
She was only 17 when she was found dead in woodland outside the Royal Logistic Corps headquarters at Deepcut in November 1995.
She had been manning a guard post alone and had a bullet through her forehead.
Pte Benton, from Hastings, had gunshot wounds to his chest when he was found in June 1995.
'Conspiracy theories'
Pte Geoff Gray, 17, from Hackney, east London, died of two gunshot wounds to the head while on guard duty last September, while Pte James Collinson, also 17, from Perth, Scotland, was found dead with a single gunshot wound while on guard duty at the barracks in March this year.
A Commons committee has further begun a separate inquiry into the series of unexplained deaths.
Mr James welcomed the new inquiry and said there were still unanswered questions about his daughter's death.
"In my daughter's case I was certainly prepared to accept that she had taken her own life, indeed I still am," he told BBC Radio 4's Today programme.
"If that was the case, there must be some very good reasons. I certainly believe there was a culture of quite sinister bullying at the Deepcut camp.
"My wife and I never really fell in line with any conspiracy at a very high level. I think if there has been a conspiracy it has been at a relatively low level.
"But unfortunately the more time goes on and the more evidence comes forward, it appears more and more that the cover-up was a little more professional."
One of Pte James's former friends in the army told her parents she had been forced into a sexual relationship with a corporal.
They have also seen the army's board of inquiry report into their daughter's death, describing an incident in which a corporal ordered her into his office and asked if she wanted to have sex, rubbing her shoulder and back, before she fled.