The inquiry follows a report by the police watchdog criticising the original investigation, which the family of Senior Aircraftman Robert Fleeting were deeply unhappy with. They have spent the past two years fighting for the case to be looked at again.
A new team of officers will now investigate the death, and is following new lines of inquiry put forward by Mr Fleeting's parents.
The couple have met with the officers conducting the inquiry, which will also review the original case.
Mr Fleeting, from East Kilbride, was found dead in September 2011 in his room at RAF Benson, Oxfordshire. The 24-year-old was engaged to be married.
An inquest ruled he committed suicide by hanging after having consensual sex with a man and struggling with his sexuality. But his parents were dissatisfied with Thames Valley Police's handling of the case and made a complaint to the Independent Police Complaints Commission (IPCC), which was upheld.
Last night, they welcomed the development and said they hoped it would get to the truth about what happened their son.
His father, Charles, 52, a council worker and a former member of the Argyll and Sutherland Highlanders, said: "It's been a long haul, but we're pleased there's a new investigation. This team is doing all the proper things the original team should have been doing two years ago."
Mr Fleeting said he had already provided officers with statements, and added: "We brought up points we thought were significant. It's a new case to them. They're taking it very seriously and they're going to do their best. They are starting from scratch, though obviously they don't have a body. But they've told us it is amazing what they can do in a cold case."
Mr and Mrs Fleeting understand the new police inquiry will use handwriting experts to analyse the suicide notes found by the body. Photographs taken of their son's injuries will also be reviewed, and a reconstruction of the scene where he was found will be set up.
The serviceman's mother Susan Fleeting, 53, a shop worker, added: "It is very reassuring. We want to get to the truth so Robert can rest in peace."
The IPCC report, published in May, pointed to a number of flaws in the original investigation, in particular that internal injuries he had suffered had "been left entirely unexplained".
It also criticised the inquiry for failing to give an adequate explanation as to how the senior aircraftman apparently hanged himself from a door-closing mechanism which was almost one foot above him.
Concerns were also raised in the IPCC report that officers had accepted the word of a key witness despite him providing contradictory statements.
Mr and Mrs Fleeting say they would have been relaxed if their son were gay, but believe he was heterosexual and happily engaged.
On the height of the door-closing mechanism, it said: "For Robert to have suspended himself from the door closer, consideration should have been given as to whether he could have done this himself, but there was no reference to any investigation … on the point."
Mr Fleeting's funeral service at Linn Crematorium in Glasgow on September 15, 2011 was attended by more than 500 family, friends and colleagues. He was cremated with full military honours.
A spokesman for Thames Valley Police said last night: "Following the appeal that was upheld by the Independent Police Complaints Commission, Thames Valley Police is conducting a review into the investigation and will be exploring new lines of inquiry put forward by Mr Fleeting's family."