Apple is tentatively planning to launch the iPhone 6 along with the final iOS8 version in a launch event in mid-September, sources reveal.

Apple, the popular smartphone maker, continues its secrecy about the launch of the next iteration of iPhone and its mobile operating system. Previous reports have suggested that the Cupertino-based tech giant will launch its iPhone 6 in September, but details on the launch date are in a flux. A new report by 9to5Mac has some sources confirming Apple's plans to launch the next iPhone model alongside final details on iOS 8 in mid-September.

Apple is "tentatively" planning the keynote address for the launch of its new hardware and software somewhere between the second and third week of September. But production uncertainties may lead to change in plans, sources add.

An earlier report this month suggested Apple is facing production issues that may hold off the launch of one of its iPhone 6 models until next year. It is widely reported that Apple will launch two iPhone models, one with 4.7-inch display size and another with 5.5 inches. The phone maker also plans to use scratch-proof sapphire crystal material for its 4.7-inch model. But Apple is experiencing problems with the larger iPhone model's new technology in the in-cell touch panel and metal casing.

The latest report from 9to5Mac echoes the delayed launch of the 5.5-inch iPhone 6 model, while the 4.7-inch version is already in testing and manufacturing phase, sources add.

With the possible launch of a new iPhone in September, Apple is also rushing to finish iOS8 so a final version of the software can be launched pre-loaded in the new iPhone. This has long been Apple's strategy; to launch new software with a new device, like it did with the iOS7 in September last year when it launched the iPhone 5S and 5C.

According to the report, Apple will also release a fifth beta of the iOS8 to developers on August 4 and a final version beta on August 15. The most recent iOS 8 beta 4 was released to developers recently and is said to be the most stable test version so far.