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 detectives will now investigate the death, and is following new lines of inquiry put forward by Mr Fleeting's parents.
The couple have met 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.
His parents welcomed the development and said they hoped it would get to the truth about what happened their son.
Dad Charles, 52, a former member of the Argyll and Sutherland Highlanders, said: "We're pleased there's a new investigation. This team is doing all the proper things the original team should have."