Controversial billboards promoting atheism today appeared in Auckland, Wellington and Christchurch, after NZ Bus refused to run the ads on bus sides.

The New Zealand Atheist Bus Campaign last year raised more than $22,000 to fund ads to run on buses, but NZ Bus declined to run them after receiving a number of complaints from the public and staff.

The group announced last month the ads would appear on billboards instead, while taking a discrimination case against NZ Bus.

The New Zealand campaign organisers had chosen three winning phrases from more than 900 public submissions to an online billboard generator.

The three slogans appearing on billboards were: "In the beginning, man created God", "Good without God? Over one million Kiwis are" and "We are all atheists about most gods. Some of us just go one God further".

The ads also featured the phrase "There's probably no God. Now stop worrying and enjoy your life", borrowed from the British Atheist Bus Campaign which caused a storm when it launched last year.

The New Zealand campaign organisers were now asking for more donations from people who wanted to see the billboards spread to more cities.

About $10,000 of the group's funds would go towards the billboards, Mr Fisher said last month.

In March, the group applied for legal representation from the Office of Human Rights Proceedings to pursue its discrimination case against the company.

NZ Bus said it declined to run the ads because the campaign had drawn a "significant reaction" from passengers and staff, with a number finding it distasteful or distressing.

"NZ Bus has the right to decline advertising that may, in its perception, be considered controversial or divisive," spokeswoman Siobhan O'Donovan said.

Mr Fisher said the billboards would get the atheist message out into the public while the group awaited the office's decision.