The South Australian Electoral Commissioner has apologised over a "deeply regrettable" error that has seen the wrong person elected to the Port Adelaide Enfield Council.

Key points: Peter Jamieson was wrongly denied a position on a council in Adelaide

Peter Jamieson was wrongly denied a position on a council in Adelaide A human error led to another candidate receiving hundreds of extra votes

A human error led to another candidate receiving hundreds of extra votes The Electoral Commission said it was "fortunate" the mistake was picked up

Adrian Wotton was incorrectly elected to the position of councillor in the outer harbor ward ahead of former councillor Peter Jamieson, because a polling officer incorrectly entered an extra 700 votes for Mr Wotton.

Mr Wotton received 447 first-preference votes in the November council election but "human error" meant that number was entered as 1,147 into the computer system, and he was elected to council.

South Australian Electoral Commissioner Mick Sherry said a polling official had not followed two crucial procedures — she had not completed a count sheet and had not reconciled the numbers entered into the computer and the hand-written count results.

Adrian Wotton was incorrectly elected to the position of councillor. ( Port Adelaide Enfield Council )

"It is unfortunate, it is disappointing, we regret that the error has occurred," he said.

"If one of those processes had been followed the error would have been picked up and rectified at that time.

"My role now is to make sure the will of the people expressed in the outer harbor ward is accurately confirmed in the results and the correct people are elected."

But it is not a simple process for Mr Jamieson to now take up the role his community voted him in to.

He had to lodge a petition with the court of disputed returns and await the verdict.

'Fortunate' the error was picked up

Mr Sherry said it was "fortunate" the error was picked up during the 30-day period of disputed returns which ends this week.

He said he took full responsibility for the blunder and had apologised to the people affected.

SA Electoral Commissioner Mick Sherry speaking about the council elections. ( ABC News: Claire Campbell )

Mr Jamieson previously served as an outer harbor ward councillor for 15 years after being elected to council in 2003.

He said he thought something was a bit odd because the numbers suggested a 10 per cent increase in the number of voters.

Usually about 30 per cent of outer harbor residents vote in council elections, but he said it was close to 40 per cent according to the statistics at the time.

"I didn't suspect anything like this at all … I just thought it was because of the campaign that was being run in my ward," he said.

"I know Adrian personally, I'm sure he's very disappointed and I feel for him.

"I've come out of this understanding one thing about our democracy and it's strong.

"Organisations like the Electoral Commission have admitted a mistake and tried to rectify it — I think we should be really happy that we live in a society like we do."

The Electoral Commission of South Australia said the polling officer involved in the bungle was experienced and had undertaken all the appropriate training for the role.

Mistake was a 'complete oversight'

Mr Sherry said the woman claimed the mistake was a "complete oversight" because it was very busy, but he said no decision had yet been made about whether she would work as a polling officer again.

"We are offering her whatever support she needs to get through this difficult time," he said.

"We have put in place processes to ensure this does not occur again."

The Electoral Commission of SA said it had since reviewed all other council results and he was confident no other errors had been made.

Port Adelaide Enfield Council chief executive Mark Withers said Mr Wotton would remain a councillor until the court of disputed returns had made its decision.

"We're incredibly disappointed that it's happened just after we got the council settled and inducted and they were working really well as a team," he said.

"(Mr Wotton) just obviously feels very uncomfortable knowing what we all know, that for him to continue to participate meaningfully in council meetings and decision making processes seems a bit odd and confusing and I guess a bit embarrassing for him personally.

"You feel for the individuals who have celebrated their success and commiserated with their loss and then completely reversed their emotions."