An advertising campaign featuring a banana flashing a strawberry and a pear has been referred to the Advertising Standards Authority - but the company director says it's getting good penetration.

The complaints against Habitual Fix, a fresh food and juice company based in Auckland's CBD, claim the adult theme behind the images is inappropriate.

The main image shows a banana opening his coat, or skin, exposing a protruding banana as a female strawberry and pear run away screaming.

Auckland resident Jackie Robson said she originally saw the image on the back of a bus ticket. "I thought, 'Bloody hell, that is outrageous.' I was shocked."

She said the adult theme, with a sexual and aggressive overtone, could give children the wrong idea.

"Even though it is just fruit there is the angry look and it is clear what the banana is doing."

In one week of catching the bus twice a day, she said the image was on the back of tickets six times.

Habitual Fix founder James Tucker said the campaign was fun and easy going and reflected the slogan "fresh food addicts".

He had received two complaints in the past month despite the image having been used for 18 months, including on a billboard downtown.

"On the back of bus tickets alone one and a half million images would have gone out over the last three months," he said. "Probably another million have gone out on the back of supermarket receipts.

"We have literally hundreds and hundreds of people saying they like it. Ninety-nine per cent say they like it.

"It was designed to get attention," he said. "The brand is starting to get penetration in the CBD."

Advertising Complaints Authority executive director Hilary Souter said the authority had received three complaints. The next step would be for the chairman to decide if there had been a breach of standards.