Mountain Equipment Co-Op (MEC) has temporarily pulled two items from its online store after customers complained the versions of the product advertised for men and women were being sold for different prices.

The product, listed as a "Castelli head thingy," is a product described as a "neck warmer, hairband, face mask, bandana, helmet liner."

The men's version of the product was listed for $30, while the women's product was listed for $35, though the only difference in the online store appeared to be the colour scheme.

The price discrepancy was pointed out on Monday by a Reddit user, who wrote they received a private response from MEC saying they wouldn't change the prices because they're set by the supplier.

"I think retailers should take responsibility in not passing the "pink tax" along to their female customers, even if their suppliers are the original source," they wrote.

The men's version of the product, advertised for $30. (MEC)

The women's version advertised for $35. (MEC)

Both the items have since disappeared from MEC's online store.

In a written statement sent to CBC News on Tuesday, the outdoor gear and clothing retailer wrote it is obliged to comply with its vendors' pricing when they have a policy in place about the minimum advertised price.

"We have reviewed the products in this case and haven't found any significant differences in product features. We are connecting with our vendor partner now and expect both items to be back online tomorrow with identical pricing," the statement read in part.

Pierre Perron, the general manager of Castelli, which makes the product, wrote in an email that the difference in pricing is based on the factory in which the items are manufactured.

"The same items can be produced in different factories with slight price discrepancy with no relation in gender," he wrote.

Pricing discrimination difficult to prove

The "pink tax" refers to the phenomenon of gender-based price discrimination, where items whose ads target women are often priced higher than similar products advertised towards men.

For example, a 2016 study found that women in Canada pay over 40 per cent more than what men pay when it comes to personal care products.

Ken Whitehurst, the executive director of the Consumers Council of Canada, said that while some products appear to be priced differently based on the gender they're advertised toward, regulators would need to investigate to determine whether a pricing difference was caused by a cost incurred in the supply chain.

"It is a very fair thing to wonder whether sometimes price discrimination is just discrimination, but it's extremely hard to identify and prove," he said.

"But if a company is taking a truly identical product in all ways and screening their customers and simply offering exactly the same product at different prices based on gender, that's going to be pretty clearly discrimination."

Whitehurst said the council's goal is to see fair pricing for all customers.

"A way to put that to the test may be to buy products across what are perceived to be gender lines and see what happens to prices," he said.