Mr Cox said the rower was sceptical of the belt but agreed to try it.
"A couple of weeks later Mahe phoned asking if he could move the velcro connector around to one side so it wouldn't interfere with his rowing action," he said.
"He went on to wear the possum belt nearly every day for the next year and-a-half, winning the world singles title and later the Olympic gold."
The history of the belt goes back to the mid-1990s when Colin and his brother Bo Cox, together with the late Sir Peter Elworthy, were pioneering the possum clothing industry. On a visit to Japan Sir Peter learned that scientists had discovered that possum fur had the same thermal qualities as polar bear fur.
Then in one of those "Eureka!" moments, Mr Cox had some seat covers made from possum pelts and after using one at a lengthy meeting noticed some pain relief in his lower back.
Taking testing a step further he made a possum pad to fit his lower back area, tied it around himself and hopped into a cold bath.
"At first the cold was intense but in a very short time my lower back started to warm up. It was enough to convince me we were on to something," he said.
For the next two years Mr Cox and his wife Bev trialled the possum belt and found that the fur "breathed", taking away moisture and perspiration from the skin as it did so.
"With wool and other fibres moisture sat on the tips of the fibres and leaving you hot, cold or clammy depending on the exertion. But possum fur seems to arrive at blood heat and then turn off like a thermostat," he said.
The biggest problem was finding the right material to bind the possum pad around the lower body and it was another two years before material used in mountaineering clothing was found.
Five years of trial and error later and the Coxes were satisfied with their product.
The next challenge was getting the message across. Mr Cox didn't like the idea of using some sporting personality simply because they were famous. He wanted the genuine article, someone still participating and suffering from back problems.
The answer came at a social event at a city bowling club when a former rower suggested they contact Drysdale.
Mr Cox said he was thankful for the countless hours clothing machinists Peter and Pat Gilbert had put in nutting out problems sowing the belt.
Meanwhile, staff at UCOL campus in Wanganui were working on a couple of minor alterations to the belt before full scale production and international marketing began.
Mr Cox was negotiating production details with Bary Knitwear in Marton and those should be finalised very soon.