Doubts about the accuracy of the Senate vote count remain until the Australian Electoral Commission agrees to publicly release the computer code it uses.

That's the view of the Australian Greens and academics who have studied vote-counting software errors.

University of Melbourne researchers recomputed the NSW local government election results from 2012, finding two errors in counting - one of which showed a candidate's chances of election significantly being reduced.

The NSW Electoral Commission on Tuesday announced it had corrected the software - originally bought from the AEC - following the study by researchers Andrew Conway and Vanessa Teague.

But it was only because the NSWEC published its full preference data and coding that the errors were identified.

When the ACT Electoral Commission released its counting code, researchers at Australian National University found three bugs which were subsequently fixed before an election.

When the Victorian Electoral Commission made its electronic voting protocol available to researchers in 2010, University of Melbourne researchers identified a security weakness which was then rectified before the state election.

However, the AEC has resisted releasing the code it uses to count the Senate vote, despite a Senate motion and a freedom of information request.

"It would be good for democracy, and good for the electoral commissions, to make election-related source code public before an election," Dr Teague said.

Greens electoral spokeswoman Lee Rhiannon said the NSW error cast doubt over the integrity of the Senate counting process.

"These revelations add further weight to the call for the AEC to open up the Senate counting code to public scrutiny," she told AAP.

"Surely the integrity of the Senate count far outweighs any commercial-in-confidence arguments for keeping the code secret."

The Australian Electoral Commission referred AAP to a decision by the Administrative Appeals Tribunal in December 2015.

In that decision, relating to a freedom of information request, the tribunal found the release of the source code for the software known as Easycount would have the potential to diminish its commercial value.

"The tribunal is satisfied that the Easycount source code is a trade secret and is exempt from disclosure," the AAT said.