A Michelin-starred street food chef is under investigation for allegedly overcharging for her signature crab omelette.

Jay Fai, 81, sells the popular dish for 1,500 Baht (34.15 GBP) from a rundown stall that has long queues every day in Bangkok, Thailand.

But the cook allegedly almost tripled the price to 4,000 Baht (91.05 GBP) when a vlogger ordered dinner from the restaurant.

YouTuber Peachii claims she visited the venue with her friend Marta, and they were both shocked when the bill arrived.

The restaurant staff allegedly told her that the higher price was applied because they had used crab from a 'better source'.

Peachii said she did not mind the price and the meal 'was delicious', but she questioned why the store charged differently from the menu.

She said her friend also enjoyed the food but was bemused when asked to pay the 'inflated price'.

Peachii said: 'I can understand that Jai Fai's crab omelette with quality crab is expensive, but I didn't order anything special and wasn't told in advance that prices vary from the menu. The menu shows 1,500 baht per dish. I only found out when the bill came.

'When a menu shows one price but suddenly the chef adjusts the size or ingredients at will, they should write a price range from the beginning. It was delicious in the end, but it spoiled the experience.'

Thailand's Commerce Ministry has now launched an investigation into the roadside stall in the Phra Nakhon district of the capital.

Wittayakorn Maneenetr, director-general of the Department of Internal Trade, said: 'The department will contact the complainant to collect additional details.

'The inquiry will focus on whether the restaurant displayed price labels accurately and whether there was any inconsistency between the listed prices and those charged at the time of payment.

'It is common for restaurants to offer crab dishes at varying prices, but they must clearly provide these details to their customers.'

Restaurants that fail to display price labels face potential fines of up to 10,000 baht (227.64 GBP), while overcharging customers has the same fine.

If a restaurant is found to have engaged in price gouging, it could be penalised under Section 29 of the Price of Goods and Services Act, which carries a potential fine of up to 140,000 Baht (3, 186 GBP) along with imprisonment for up to seven years.

Jay Fai, which means 'Sister Mole' after the mark on her face, was awarded a Michelin Star in 2018 and has been visited by global celebrities such as Jack Ma, Ed Sheeran, and Lisa from Blackpink.