Costco has reportedly discontinued the popular Kirkland brand soy milk after its sudden absence from shelves.

The item, which is sold in vanilla and plain flavors in 32 fluid ounces for $3 or 12-count boxes for $20, recently disappeared from stores and one Reddit user claims to have reached out to Costco directly, receiving an email response from the company confirming that they had all been discontinued.

"Thank you for your feedback regarding the KS Soy Milk. Unfortunately, the KS Soy Milk was discontinued due to slow sales," the Costco representative wrote in the email, according to Redditor @Schrodingerscastuc. "However, we plan on bringing in a branded Soy Milk as an item rotation throughout the year. The next rotation is due to arrive in August."

Another Redditor claimed in a separate thread that the soy milk disappearance was caused by heated negotiations over the product's price.

"I just talked to the manager of the flagship Costco," Reddit user @rannmann wrote. "He said the manufacturer was giving them a bad price when the contract renewed, so they're not renewing the contract right away. They're trying to find other vendors who give good quality for value, while simultaneously talking down the old vendor to a more reasonable price. It will definitely come back in stock, but it's not entirely clear when."

Earlier this year, Costco confirmed its reported plans to replace Pepsi products in its soda fountains with Coca-Cola beginning this summer.

"This summer we will be converting our food court fountain business back over to Coca Cola," said CEO Ron Vachris during a shareholder meeting earlier this month via the Daily Mail.

Costco also increased its annual membership fees for its U.S. and Canada customers in September for the first time since June 2017, the Associated Press reports.

The "gold star" and business membership price increased from $60 to $65, while the executive membership fee increased from $120 to $130, effective September 1. The big-box warehouse club retail chain's membership offers discounts on food, gas, home insurance and grocery items, as well as an annual 2% reward on qualified purchases.