Small and fluffy, with large eyes and rabbit ears, Chinese-made "Baby Three dolls" became a must-have among Vietnamese kids and Generation Z earlier this year and had been flying off shelves across the country.

That was until an online backlash began over the "Town rabbit V2" model of the doll -- and a marking on its cheek that was said to resemble China's so-called "nine-dash line".

Beijing has long used the line to justify its claims over most of the resource-rich South China Sea, often to the displeasure of Vietnam, which also claims parts of the waterway.

In response to the online outcry, the industry and trade ministry ordered an inspection of toys supposedly displaying the nine-dash line, which it warned were "affecting national security and territorial sovereignty".

Vendors in Hanoi told AFP that most of the offending dolls had been pulled from shelves, but their once-booming business has been shattered, with sales of all models vastly down.

Le, who declined to give her full name, said she used to regularly sell 100 Baby Three dolls a day for up to $20 each, but her sales had dwindled to almost nothing, with just a few now flogged at reduced rates.

"Almost all children started to boycott (the dolls) because they saw it as a nationalistic issue, thinking that buying Baby Three was unpatriotic," she said.

"I've invested so much money into this... it feels like such a waste," she added.

- First 'Barbie', now this -

According to data cited by state media from YouNet ECI, an e-commerce data analysis platform, the average selling price of Baby Three on Shopee and TikTok Shop plummeted by half in the first 10 weeks of 2025.

Vu Tu, 19, told AFP that the toys were "cute and adorable" but the "nine-dash line scandal" had put him off.

"In my opinion, toys with the nine-dash line affect Vietnam's sovereignty and I don't support them," he said.

The controversy comes as the website of Chagee -- a Chinese milk tea brand due to open its first store in Vietnam -- was flooded with angry comments and threats of a boycott last week over a nine-dash line map featured on its website.

In 2023, "Barbie", the fantasy comedy film directed by Greta Gerwig and starring Margot Robbie and Ryan Gosling, was banned from cinemas due to scenes featuring the nine-dash line.

And in 2018, Vietnam cut a scene from the romantic comedy "Crazy Rich Asians" that featured a designer bag with a map of the world showing the disputed South China Sea islands under Beijing's control.

The South China Sea is home to valuable oil and gas deposits and shipping lanes, and several of China's neighbours have voiced concern that Beijing is seeking to expand its reach.