A video posted on social media on June 8 has attracted more than two million views, showing the tourist buying the snack while walking near Hoan Kiem Lake.
According to the footage, the tourist repeatedly asked for the price, but the vendor did not respond and instead quickly placed multiple fried dough balls into a plastic bag.
The vendor stopped only after the tourist indicated he did not want any more. The bag contained about 10 to 11 pieces.
The tourist was initially told the bag cost VND 150,000. However, after handing over a VND 500,000 note, he received only VND 80,000 in change, suggesting he had been charged VND 420,000.
Many social media users questioned the price, noting that similar fried dough balls are typically sold for around VND 2,000-3,000 each.
A representative of Hoan Kiem Ward Police said authorities were aware of the incident and were verifying the circumstances.
The case follows several previous incidents involving alleged overcharging of foreign visitors in Hanoi's Old Quarter.
In recent years, local authorities have fined street vendors and service providers for charging excessive prices to tourists, including cases involving snacks, fruit and transport services.
Tourism officials have advised visitors to confirm prices before making purchases and called for stronger enforcement of price transparency at tourist destinations.
