The Electoral Commission of South Australia has uncovered more than 600 ballot papers that were not counted in the recent state election, including dozens from the closely contested seat of Narungga on the Yorke Peninsula.
Narungga has been declared for One Nation’s Chantelle Thomas, who won the seat by a margin of just 58 votes.
The electoral commission has ordered a further count in Narungga since the discovery.
It says the ballots include 77 unopened absent ordinary ballot papers and four declaration ballot papers that were returned in the neighbouring district of Stuart.
Acting commissioner Leah McLay said they were among 642 votes for electorates across the state that were found in three sealed boxes returned to the electoral commission recently, but a new count would only be conducted in Narungga, which had the thinnest margin of 0.1 per cent.
Ms McLay said she had contacted all candidates today to notify them of a further count to ensure the integrity of the Narungga result.
“Let me be clear: the result has already been declared, 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 the subsequent recount,” she said.

Leah McLay says the count will ensure the integrity of the election. (ABC News: Ben Pettitt)
If the count reveals the result of the election could change if the ballots were included, Ms McLay said the commission would then seek legal advice about petitioning the Court of Disputed Returns to decide what to do.
The new count will take place on Friday.
“We have not investigated what the cause of the error was,” Ms McLay said.
The electoral commission declared Ms Thomas the winner in Narungga on April 2, over Liberal Tania Stock, after a recount because of the razor-thin margin in voting.
The win gave One Nation four seats at the state election, including Narungga, compared with the Liberals’ five.

A recount was conducted in Narungga on April 1 and 2. (ABC News)
Liberals want clarity
Liberal leader Ashton Hurn told 891 ABC Adelaide the electoral commission “have some explaining to do”, although the new count was unlikely to change the result in Narungga.
Although the electoral commission said it had alerted all candidates, Ms Stock said she had not been contacted and was unaware of its statement when contacted by the ABC.
“I’ve had no official confirmation of extra votes being discovered,” she said.
“I find it unusual if boxes were being opened and votes being counted without scrutineers being present.
“If there are further votes that haven’t been accounted for, we need to understand exactly where they’re from and we need to make sure they’re counted and scrutineered in the way that’s required.”

One Nation won the seat of Narungga by 58 votes. (ABC News: Trent Murphy)
Asked if she was hopeful the result might change, Ms Stock said: “We’ll just have to wait and see.”
“It is a very close result and every vote counts, so it’s really important that the process is conducted professionally,” she said.
“I’d appreciate any official notification from ECSA and how they are planning to proceed with the vote count.”
The electoral commission has already faced criticism over how the poll was run on March 21, including around understaffing, delays on election day caused by difficulties logging into the electronic electoral roll and how the First Nations Voice vote was handled.
It has previously said it would review how the state election was handled, as it does after every election.
Deputy Premier and Special Minister of State Kyam Maher said the government would also commission an independent review.
“I think people would be rightly concerned, but I don’t think anybody should have any concern that it’s not a free and fair election, as we’ve always seen in South Australia,” Mr Maher said.
Ms McLay would not say where the uncounted votes had been cast, but Mr Maher said they had come from the Port Pirie early voting centre.