Size definitely does matter, says a shocked father left struggling to explain exaggerated genitals on carvings in Hamilton's Te Parapara Garden to his young children.

Phillip Stevens was exploring at Hamilton Gardens with his four children, all aged under 10, last weekend when they came across the Maori themed garden for the first time.

His nine-year-old son had noticed the carvings as they entered the garden. "He asked us `is that a penis?'," said Mr Stevens. "It was pretty obvious what it was, but as you go on there's one with big testicles, then there's one holding it. We tried not to make too big a deal of it, and just told them it was a bit inappropriate."

He said nude works from European art traditions would not offend him in the same way as the genitalia were of more natural proportions.

"The majority are the same size as their legs. I can imagine there's a few kids out there who would really be put off by it. I'm surprised nobody has raised it earlier," Mr Stevens said.

However, Nga Mana Toopu O Kirikiriroa spokesman Wiremu Puke said the carvings were based on early styles produced by carvers in the Waikato basin, and saw no reason to warn visitors who might be offended.

"There are drawers and drawers in the Auckland Museum of carvings that have mutilated genitals due to the early missionaries. That's probably one of the most visited gardens, and people are usually amused or intrigued by the carvings."

Explaining the prominent genitals was an issue for parents, he said.

Mr Stevens said he had decided to speak out because he felt too often people just left it up to others to raise issues.

It was about financial accountability as well as the potential for offence, he said. "If rates are paying for these, surely someone would have the common sense not to put them up. On the day we were there, there were (several) Muslim families in the gardens," Mr Stevens said.

City council parks and gardens manager Bill Featherstone said to his knowledge no complaints had been received by council about the carvings in the garden.

Explanatory signage had not been put up to avoid compromising the authenticity of the gardens. However, an information booklet was being prepared for visitors.