Police are investigating a death threat against a political organiser in relation to a possible Super City voting scam in South Auckland.

Citizens & Ratepayers campaign organiser Jim Stephens received a letter mentioning a "hit list" and "shooters" if the right-leaning ticket did not desist from maligning "our winning candidate Daljit [Singh]".

It was purportedly signed by "Daljit Singh supporters".

Last night, Daljit Singh, one of two Labour Party candidates in the Papatoetoe subdivision of the Otara-Papatoetoe Local Board, was "100 per cent sure" none of his supporters had sent the letter.

"We are very happy if the police have any information they want to discuss with us. We are absolutely law-abiding citizens and have not been involved in any criminal activities."

Last week, police visited his real estate office and removed his computer laptop. He said that since then, his lawyer had been in contact with the police but he had not spoken to them.

Detective Inspector Mark Gutry, who is leading 40 police investigating more than 300 falsely enrolled voters in Papatoetoe, said the threat against Mr Stephens would be considered as part of the case.

Mr Stephens said he received the letter at his home in Hillsborough on Saturday. As the authorising agent for C&R, his name and home address are included on billboards and other election material.

Mr Stephens believed the message was addressed to C&R and not him specifically. He had discussed the letter with his wife and was being vigilant at home.

The two leading contenders for the Super City mayoralty, Auckland City Mayor John Banks and Manukau Mayor Len Brown, have condemned the possible voting scam.

Mr Banks said the public were witnessing events with total disbelief and this was undermining confidence in the elections.

"This strikes at the heart of a modern, democratic nation and we have to get on top of it. Maybe after the election we have to go through these votes ward by ward and voter by voter. Who knows what the police are going to come up with."

Mr Brown said the message he was picking up in Papatoetoe was that people were not happy about the enrolment irregularities and as the mayor of the city he was not happy either.

Labour Party president Andrew Little said his organisation was co-operating with the investigation. Anyone found to have acted improperly or unlawfully would face the full consequences of the law.

Dr Nagalingam Rasalingam, president of Ethnic Voice New Zealand, said the voting scam had left a bad taste among ethnic people. He hoped the culprits would be brought to justice.