A complaint has been lodged with the Chief Electoral Officer because of a report a Labour Party volunteer coerced a voter to vote early in the Mt Albert by-election.
ACT Party candidate John Boscawen says he filed the complaint following a report a Labour supporter told a Chinese immigrant it was illegal not to vote in New Zealand.
The man reportedly told the Labour volunteer he did not want to vote until the by-election.
The volunteer is said to have told the man it was safer to vote now as missing voting on polling day was against the law.
Mr Boscawen says he is concerned the man was coerced into voting early, which could effect the way he voted.
Labour candidate David Shearer says the incident was a misunderstanding.
The by-election is to be held on 13 June. The seat has been held by Labour since it was promulgated in 1946.