The results are from an audacious search that has been described as part of CSI, part Where in the World is Carmen Sandiego?
That is if Carmen Sandiego was a platypus and not a computer video game character from the 1990s.
Victoria has a statewide picture of how its platypus population is faring thanks to The Great Australian Platypus Search.
The search was held from August to September last year, with citizen scientists asked to collect water samples from more than 1,500 waterways across the state.
Scientists at EnviroDNA ran water samples through their labs looking for environmental DNA, also known as eDNA.
traces of wildlife DNA were shed from the animals into the environment, according to the eDNA.
Scientists used the information to track some of the state's stealthiest critters into previously unknown hideouts.
I don't know if it's exciting, but filling areas where we didn't have platypus data before was one of the big goals of the project, said Josh Griffiths, platypus ecologist.
The results were largely what we expected - the platypus were largely where we thought they were and not where they weren't thought to be. The platypus was listed as threatened for the first time in Victoria last year and was endangered in South Australia.
According to an EnviroDNA spokesman, the data would be released to the public soon, and that a similar program is expected to start in New South Wales in the near future.
The platypus search turned Victoria's waterways into a quasi-crime scene, with amateur sleuths slugging through the bush taking samples that would hopefully uncover vital clues.
Early results indicated promising returns in western Victoria, particularly in the Wimmera region.
The Mackenzie River has a localised population and it looks like that population is expanding a bit further, which is great, Mr Griffiths said.
There were no platypuses found in smaller tributaries off the major rivers, although strong numbers were recorded in the Glenelg and Hopkins Rivers further south-west near Warrnambool.
One of the big things to come out of this is to find out where those populations are in strife, Mr Griffiths said.
That is how we can find out where we can help the population so that they're still around in another 50 or 100 years. The survey was spearheaded by the not-for profit conservation organisation, the Odonata Foundation, with funding from the state government and numerous philanthropists.
It was hoped that the results would be a baseline for future generations' learning.
This data will complement many years of visual observations and scientific studies to give us the most comprehensive understanding of the platypus distribution we have ever had. Mr Griffiths said the information would be invaluable for catchment authorities and those charged with protecting the state's waterways.
Citizens could help to stop the decline in the population, as they collated the information.
Everyone was very conscious about conserving water when we went through the drought, but I think it's probably been a bit slacker since.
Every time we have a shorter shower or don't water gardens in the middle of the day, every litre of water we save can potentially be returned to the environment for platypus and fish and turtles and everything that's dependent on it.