Auckland Mayor Phil Goff is promising an investigation into Sephora after it allegedly dumped waste into drains following its Auckland opening.

Photos posted to Sephora's Facebook show large amounts of paper being scattered into the air to celebrate the first day, and images sent to Newshub show Sephora workers washing and sweeping the paper litter into the drains.

"We worked closely with Auckland Council to meet all requirements (including waste management and health and safety plan) for its approved event permit to ensure the confetti was safe for the environment," a Sephora spokesperson told Newshub.

"The confetti used was bio-degradable, water-soluble and plant-based. This is now an Auckland City Council matter."

However Goff says the Council didn't approve these actions.

"Unacceptable for anyone, particularly a major retailer, to be polluting our waterways," he tweeted.

"Totally untrue that Council granted permission for such behaviour - waste must be collected and disposed of responsibly. I'll be writing to Sephora for an explanation and Council will investigate."