After forwarding the photo to the Council's compliance team Casey contacted the Human Rights Commission about the sign.
"It seems to me that this one looks like this one could be discriminatory so I thought I'd send it to [the commission] and ask for their judgement on it.
"If the Human Rights Commission rule that it's discriminatory then it is and it's kind of wider than just that one shop. There has been a lot of discussion in recent weeks and months about the burka and you know, it's maybe time for a ruling."
She also posted a photo of the sign to her Facebook page and was surprised at the reaction it received from people.
"I didn't realise there was so much emotion behind [this issue] until today - that people have really strong opinions. I just think everybody to their own, each to their own, I like to give people as much leeway as they need to be who they are," Casey said.
"I'm not questioning the motives of the business owner. I'm just saying that it doesn't feel right that you should be discriminating [against] that particular group of women.
"I've never met the owner of the shop so it's not really about them. It's about the issue. The issue is: is any shop owner above the law which says you can't discriminate in this way?"
Banks and other large business allow people wearing burkas to enter, Casey said.
"I've already looked into the BNZ about what they do. They just ban hats, sunglasses, hoodies and helmets.
"I'd like to find out what is the actual answer here. What is the rule? Because it's not just the small business, it's for the rest of New Zealand."
When the Herald contacted the owner of the store, Llannys Burgess, for comment she said: "I can't be bothered".
"Go away and talk to someone who cares."
She said she put the sign years ago after a man came in and attacked a customer with a machete and she feared for her safety being a woman alone in the shop.
"I have gone to the tribunal and won."