Earlier, Bloomberg's Mark Gurman had reported that Apple was investigating the issue and had yet to give stores or customer service representatives guidance. Now, he says Apple has responded, asking affected customers to contact AppleCare for a replacement unit.

"We are aware of an issue impacting the inner display on a small number of iPhone Duo units. If users experience issues with their iPhone Duo display, they should contact AppleCare for a replacement," Apple said.

This comes as a relief for affected customers, as the display repair costs half the value of the iPhone Duo, nearly Rs 1.5 lakh in India and $999 in the US, without an active AppleCare+ plan.

Additionally, in a statement to MacRumors, Apple said that it was aware of the inner display issue, but it did not specify the cause of the failures.

All of the reported screen damage issues demonstrate a common pattern. The crack is seen as a vertical line above the hinge and some horizontal lines running to the right side of the fold, converging at a spot right below the centre point.

Repair and teardown specialist iFixit believes that it has found the reason for the screen damage and says that it is connected to the hinge mechanism. Acknowledging the possibility of multiple culprits for the issue, the publication narrowed it down to the screen's curved fold coming down onto the centre bar and creating a small stress hotspot near the reported break location. The image attached below visualises the stress spot.