The shock victory of One Nation candidate Chantelle Thomas in the South Australian seat of Narungga has been thrown into doubt after election officials uncovered dozens of ballot papers that were never counted. 

The Electoral Commission of South Australia has ordered yet another count after discovering 81 overlooked votes just weeks after the razor‑thin result was declared.

Thomas was declared the winner on April 2, defeating Liberal opponent Tania Stock by just 58 votes following a recount, a margin now dwarfed by the uncounted ballots. 

The stash included 77 unopened absent ordinary ballot papers and four declaration ballot papers mistakenly returned to the commission with votes inside. 

All were located in three sealed boxes linked to Narungga and neighbouring Stuart. 

A recount will take place on Friday. 

Acting Electoral Commissioner Leah McLay said the discovery prompted immediate action, with all candidates notified of a further count. 

McLay said the recount would not necessarily overturn the result of the election, with Thomas already declared the winner by the electoral commission.   

'The purpose of the count is for the commission to determine whether the result would have differed had those ballots been included in the initial count and subsequent recount,' she explained. 

When pressed on what would happen if a recount resulted in a win for the Liberals, Ms McLay said the matter would ultimately be decided by the courts.

'If the recount was to indicate that, then we would seek Crown advice and look to the Disputed Court of Returns,' she said.

Thomas said news of the recount was 'very disappointing' for voters in Narungga, saying it only extended a period of uncertainty for the local community. 

'This is very disappointing for my community in Narungga,' she told the Daily Mail.

'We're being forced to wait, again, to see who will be Narungga's representative in Parliament.'

Thomas said the discovery of uncounted ballots raised broader concerns about the conduct of the state election.

'Let's be clear: this raises serious questions about the integrity of the South Australian election, whether the electoral commission was fully prepared for it, and how Labor's new electoral laws, passed with Liberal support, impacted the electoral commission's preparations,' she said.

Thomas said she, like other candidates, would now have to wait for the outcome of Friday's count before responding further. 

'Like everyone else, I'll have to wait for the count on Friday,' she said. 

'Afterwards, I'm sure there will be more to say about it.'

South Australian Opposition Leader Ashton Hurn said it was now up to the Electoral Commission to move swiftly and provide much-needed 'clarity'. 

'Who knows what this will mean for the seat of Narungga, but that's why I think the electoral commission need to provide some clarity quickly,' she told the ABC.