Fox News understands that the new computers will come with Intel's Ivy Bridge processors on board, offer better graphics and include USB 3.0 support.
The current generation iMacs, powered by quad-core Intel Core i5 chips, were rolled out in May last year in 21.5- and 27-inch variations.
Apple's next generation iMac will allegedly offer expanded SSD capacities and a slimmer form factor thanks to the removal of its optical drive. Whether the device will sport the company's patented Retina display has become the subject of intense speculation.
The Cupertino-based firm announced new additions to its MacBook Air and MacBook Pro ranges at the Worldwide Developers Conference 2012 in June.
Apple will unveil its next generation iPhone on September 12.