More reports are suggesting the iPhone 8 could be delayed (AAPL)

But there's increasing evidence that the redesigned iPhone, often called the iPhone 8 or OLED iPhone, could be announced in September but delayed until later in 2017 — perhaps by several weeks, according to a research note from Drexel Hamilton analyst Brian White distributed to clients on Friday.

White cites a contact with knowledge of Apple's Asian supply chain who is increasingly "emphatic" that Apple's new 3D camera is facing challenges that could result in delays:

However, our contact strongly believes the 5.8-inch iPhone 8 will be delayed by several weeks due to challenges around the 3D sensing technology but still in time for the December holidays. This is not the first time that we have heard about a potential delay with a new iPhone; however, our contact was so emphatic about the delay that we are taking this data point more seriously. Since it is only April, this situation could improve.

One possibility that White lays out is that Apple could announce the redesigned iPhone in September, like it has for the past few years, but instead of it going on sale shortly afterwards, it would go up for pre-orders instead.

This would be a launch strategy not too dissimilar from Apple's most recent new product, the AirPods wireless headphones, which were announced alongside the iPhone 7 last September but didn't go on sale until December 13. However, AirPods were not available for pre-order when they were revealed.

The 3D camera is expected to be a banner feature on the redesigned iPhone, which is expected to launch alongside two other new models that are more similar to the current iPhone 7 and iPhone 7 Plus. Drexel's research suggests half of the iPhones Apple plans to manufacture will be the new, redesigned model.

The 3D camera will be critical for Apple's ambition in augmented reality, a new technology that mixes the real world with computer graphics, that Apple CEO Tim Cook is fond of discussing in public. White also suggests that the 3D camera could have a facial recognition feature that won't be fooled by a photo, like the bug that's affected Samsung's new Galaxy S8.