Samsung’s flaming handsets pose a huge problem for the company’s very future because of what appears to be one of the most expensive mysteries ever: How do they keep blowing up?

The company has announced that it has stopped selling the phones and that anyone with one should turn them off. But the most terrifying part of the warning was that it applied to the replacement phones – Samsung, after having said it had fixed the problem, has said that those fixed handsets are prone to blowing up too.

During its global recall last month, Samsung said that the phones were overheating and then catching fire because there were problems in how it had made the batteries. It would replace all of the previously made phones with new ones that had working batteries and the fires would stop, it said.

Exploded Samsung Galaxy Note 7 - in pictures Show all 7 1 /7 Exploded Samsung Galaxy Note 7 - in pictures Exploded Samsung Galaxy Note 7 - in pictures Here are some pictures of exploded phones that are circulating online Exploded Samsung Galaxy Note 7 - in pictures Exploded Samsung Galaxy Note 7 - in pictures Exploded Samsung Galaxy Note 7 - in pictures Exploded Samsung Galaxy Note 7 - in pictures Exploded Samsung Galaxy Note 7 - in pictures Exploded Samsung Galaxy Note 7 - in pictures

But since then at least five of the phones appear to have exploded in the US. That included one that happened on a plane and led to it being evacuated.

Each of the phones reportedly had the green battery icon that’s included on new Samsung handsets and marks them as being safe.

The batteries for Samsung’s Note 7 – not the company’s biggest selling model, but its flagship and most admired phone – are made by two companies. Initially it was thought that there were perhaps problems with one company’s batteries, and so by using only one or fixing that issue the problems would end.

But the new reports suggest that the phones have something else wrong with them. Safety authorities have said that they have found the possibility of a new defect in the phone – potentially not connected to its batteries.

"The improved product does not have the same defect,” said Oh Yu-cheona senior official at the Korean Agency for Technology and Standards which oversees product recalls. “That's why we think there is a new defect.”

If that is the case then it will likely lead to the entire phone being scrapped. Phones are made on long cycles, meaning that any central problems with the design of the handset probably couldn’t be fixed.