A Snowy Hydro worker involved in the 2013 search for a hiker missing in Kosciuszko National Park believes authorities may have skimmed over key pieces of evidence that point to a specific area where the man may have gone off course.

Project site manager Terry Mulligan assisted with the search for Canadian Prabhdeep Srawn who disappeared during a storm on May 13 while walking on the popular Main Range Trail. A massive four-week search and subsequent summer searches failed to find any trace of the missing man.

On May 22 last year, two of Mr Mulligan's colleagues were clearing access tracks around the Lady Northcotes Canyon area, when they reported over the radio they had heard a voice calling out from The Sentinel, a steep peak above.

Mr Mulligan, who was at the other end of the 2.4km long Siren Song Creek access tunnel, went through to investigate.

"About 30 seconds after I arrived, we all heard it again, and I can tell you, that was no wind, lyrebird or trees rubbing together ... it was like a very distant cry," Mr Mulligan said. "There were so many coincidences that day, we thought for sure he was going to walk out of the scrub any minute and we'd be loading him into the back of the car."

Several search helicopters were sent in to investigate the voices but failed to find anything in the steep, boulder-strewn scrub. Mr Mulligan said another searcher with access to the data had shown him triangulated signals from Mr Srawn's mobile phone which also pointed to the area the men had heard the noise.

Mr Mulligan said he had been prompted to come forward after Fairfax Media reported new evidence last Saturday from a back-country skier who had heard what are believed to have been similar cries for help days earlier in the same area. He was also concerned that police had not given enough credence to the reports he and his colleagues had made.

"It all points to the face of Sentinel, and if they did it properly - get a heap of people and sweep down that face two meters apart - then you'd be able to know for sure, but I don't think they'll find him unless they take another look at Sentinel," Mr Mulligan said.

But NSW Police Inspector Rod Smith who took over the case said the entire Sentinel area had been covered extensively at the time, both on foot and by helicopters equiped with infra red sensors flying slow and low.

"I can reassure you that the area known as The Sentinel was certainly not overlooked. It was covered extensively at the time, particularly so after the report of voices being heard. I have GPS maps that depict the specific areas that were searched by land and air. This shows significant searching around this area," Inspector Smith said.
He said the ground searches had been particularly treacherous, with one member of the search team suffering a broken shoulder and another a back injury after falls in the area.

"Mr Mulligan is obviously not aware of the full search information and data. Pings from the phone and footprints do not necessarily indicate The Sentinel as the most likely location of Mr Srawn, however it was certainly not discounted as suggested."