Videos posted online show people using lighters and even a blow torch to try and break down Chicecream, reports Daily Star.

None of the heat sources made any impression on the sweet treat which can withstand a naked flame or an hour in an 88F room.

Dubbed the “Hermès of ice cream”, Shanghai-based Zhong Xue Gao has been popular in major cities across the mainland, despite its relatively high price of about 20 yuan (US$3) for an ice cream bar, several times the cost of most of its competitors.

Some of its premier-edition ice creams are sold at 70 yuan (US$10.50) or higher, report South China Morning Post.

Several videos of the ice cream have now gone viral on the social media platforms.

Earlier this week, a viral short video clip showed an internet user testing a Zhong Xue Gao brand ice cream by burning part of it with a lighter and showing that it does not melt, China News Service reported as quoted by South China Morning Post.

An officer from local regulator the Shanghai Market Supervision and Management Bureau said on Tuesday that they were aware of the videos and said it is investigating the case.

“The test results from professional testing institutions should be more authoritative,” the official told the newspaper. “To our naked eyes, the ice cream did not melt. But this conclusion would be better supported by scientific data.”