An anonymous source, claimed to be an employee of Verizon, told TechCrunch that the US telecoms giant was restricting all its staff from taking any holiday between September 21 and September 30.
Apple is expected to announce the new iPhone - often referred to as the iPhone 5 despite it actually being the sixth generation of the handset - on September 12.
The firm tends to release its new mobile products on Fridays to give them a full weekend of sales, similar to the approach taken with blockbuster movies.
Taking into account the Verizon source's information, this would suggest that sales will start, in the US at least, on September 21, as Verizon would want all its staff focused on what could be the biggest product launch in Apple's history.
Last year Apple announced the iPhone 4S on Tuesday, October 4. The phone went up for pre-order on the Friday (October 7), and was available in stores a week later on October 14.
There have been reports that Apple will use the launch event to also announce its rumoured Apple iPad Mini, a small-screen version of the iPad tablet.
Sources within Apple European resellers told MacRumors that they have been told by Apple to make new space in their display sections, suggesting that a new product is coming.
Some sources say that older products such as the Mac Pro, Mac Mini and certain iPods are being moved out to make space for a mystery new product.
However, other reports have suggested that Apple will not look to overcrowd the September 12 launch event with two major products, and instead just announce the iPhone 5 as expected.
The firm could then hold a separate event for the iPad Mini in October, but still look forward to having a bumper Christmas with both products on sale in key markets, including the UK.