ON YOUR BIKE: Jonathan Pielmeier, 21, says he encountered rude staff at a local supermarket when he was denied alcohol.

Rules are rules, as a thirsty German tourist discovered to his dismay when he was refused beer at a New Plymouth supermarket.

Jonathan Pielmeier, 21, thought an official German identity card would be enough when he tried to buy alcohol at a New Plymouth Countdown.

The card is an official and compulsory document recognised in most European Union countries, and displays a replica of the ID page of his international passport.

"I wanted to buy a packet of beer, they said ‘I know you're old enough, but your ID doesn't count," he said.

However Lloyd Crow, the manager of enforcement at the New Plymouth District Council, said the law states shoppers who appear under 18 must provide a current passport, New Zealand drivers licence, or an approved age card.

The law has been the same since 1989, with a slight change in wording made in 2012.

"Not all tourists are aware of New Zealand laws. Is that how we should be treating them?"

New Plymouth woman Anthea Poulton who was at the supermarket with Mr Pielmeier said she was just as confused as he was when check-out staff refused him. "They said ‘you have to have a New Zealand ID' and he's like ‘I'm German'."

The 21-year-old tourist is travelling around New Zealand on a bicycle, with a surfboard attached to the back.

It was the second time he had been refused alcohol in New Zealand, and Ms Poulton said it had also happened to a number of her homestay guests in the past. Ms Poulton tried to buy the six-pack after her guest was refused but was also denied.

Ms Poulton suggested the supermarkets better advertise the laws, particularly as many don't speak English.

A Countdown spokesman said the store had this information displayed around the checkouts and on the wall so customers were aware.

"We're sorry for any inconvenience or frustration that the customer experienced as while we stand behind our ID25 policy, we certainly want to make sure this is communicated clearly and professionally to customers."