Miffed, he called the New Zealand Transport Agency within days to seek a new one.

"I picked it up on Tuesday ... I've already had people pointing and laughing at me." Trathen added that just driving it off the car lot he was subjected to sniggers.

"I'm definitely not homophobic, I just want another plate."

When he called NZTA, he was told the numbers could be changed for something less suggestive than "69" at no cost but changing the letters would be a different story.

"The person I spoke to said: 'Oh just hold the line, I'll be putting you on to our senior adviser'. In a minute or two of waiting, they came on and there was a bit of a chuckle in their voices. The guy said 'I can change the numbers for you but it's still going to be GAY'."

Trathen checked online to see if the registration number "GAY69" was acceptable enough to be issued through Plates.co.nz.

This was the reply: "Oops! we can't sell this one. Have another go ... because we have a high public profile, we are required by the government not to sell plates that could cause offence to the wider public community."

Grant Giller of Plates.co.nz seemed surprised by the message. He said the website had issued the plates "GAY1" and "GAY".

NZTA spokesperson Andy Knackstedt said new registrations being issued at the moment all started with the letters"GAY". One thousand of each letter series were issued and the current series was up to about 700.

He said the agency had received a few dozen requests from motorists for a different letter series.

While some series such as "FAG" and "FKN" were skipped "due to the potential for offensiveness", "GAY" was not considered offensive. He said choosing to not issue the series could also be deemed offensive or discriminatory.

"We acknowledge this is quite subjective. Some people may not want that series but there's a lot of people who equally would like it."

NZTA allows motorists to change their registration plates to another series of letters and numbers for a small fee of $14.