Truglia, who served in the SAS (Special Air Service) and SBS (Special Boat Service) for 20 years, posted "Let's do this" on his Facebook page as he boarded the chopper for the fateful stunt on Thursday.
Ex-military colleague Phil Tunnicliffe said: "We have not been able to find out much about what happened. The Chinese company he was working for are trying to keep things under wraps."
"He had meant to be attempting the stunt on Tuesday above the Wulong National Park but it had been put off until Thursday because of heavy mist and fog."
"All we have been told is that there was a fall, but that does not make sense to us. Steve was a professional stuntman and had done these types of abseils many times."
Steve's girlfriend was informed of his death via a text message from a Chinese woman.
The Foreign Office said: "We have offered assistance to the family of a British national who has sadly died in Chongqing, China. Our thoughts are with them at this difficult time."