An announcement posted on Burger King's official website on Monday indicates that sales of the Whopper will cease from Sunday. (BKR)

The announcement from Burger King's South Korean operator that it would stop selling its popular Whopper lineup has stirred up controversy and mixed opinions over whether it is merely a marketing stunt or not.

Early Monday morning, Burger King informed customers through its website and mobile messenger KakaoTalk about the end of Whopper sales.

"Whopper sales will end after 40 years," the announcement read. "We thank everyone who has loved the Whopper all this time."

According to the announcement, sales of Whopper products were to continue until Sunday. However, no reason was given for the discontinuation.

The announcement has elicited mixed reactions from consumers, with some expressing disappointment at the decision, while others suspect it might be a marketing ploy rather than a genuine discontinuation.

"Is this really happening?" "Could Burger King be confusing today for April Fools' Day?" and "I hope they bring it back after a makeover" were among comments expressing disbelief in the announcement, which have continued to flood online communities.

Later in the day, the company issued another announcement reiterating the decision to cease Whopper sales. This time, it encouraged customers to expect various promotions planned in celebration of the Whopper's 40th anniversary, hinting at a "revamp" of the Whopper.

Staff at Burger King stores also appeared embarrassed.

“Certainly, Whopper sales will cease starting Sunday, as we want to introduce more diverse flavors to our customers,” muttered an employee at a Burger King store in Jongno, right across from the headquarters of BKR, the South Korean operator of Burger King.

“We'll still be selling the Whopper after Sunday. But the recipe will change slightly,” another employee interjected.

Additionally, menu items containing the word "Whopper" -- such as the Monster Whopper, Cheese Whopper, Bacon Cheese Whopper and all varieties of the Whopper lineup -- appeared with an orange label declaring "'Goodbye Whopper" on the fast-food chain’s official website.

An official from Burger King’s customer service center stated that items marked with the orange label may be affected by the upcoming change, while dismissing the notion that Whopper sales would cease altogether.

BKR has not yet released an additional official statement on the matter. The Signature, BKR’s public relations agency, also stated that it has no further comments beyond BKR’s announcement.

The Whopper has been a staple of Burger King's menu in South Korea for some 40 years, since the opening of its first store in Korea in 1984.

BKR is wholly owned by Hong Kong-based Affinity Equity Partners. After years of operational losses, the company became profitable last year with 6.5 billion won ($4.78 million) in net profit.