It is set to be the biggest phone Apple has ever produced - with the largest model believed to have a 5.5inch screen.
In fact, the new iPhone 6 handset is so large, it is believed Apple has created a special 'one handed' mode so people can east navigate and type on it.
The feature is expected to be included in Apple's iOS 8 software, also being released next week.
'To deal with concerns that a bigger phone will make typing with one hand difficult (the current iPhone has a four-inch screen), some changes to the design of the iPhones’ user interface will allow people to type or use apps with just one hand; there will be a one-handed mode that can be switched on and off, two employees said,' the New York Times claims.
Apple is expected to unveil larger 4.7- and 5.5-inch models, both with fingerprint scanners and 128GB storage options.
KGI analyst Ming-Chi Kuo believes the iWatch will also be unveiled, with 8GB of internal storage, and 512 MB of RAM.
The smartwatch may come in male and female versions, with flexible screen sizes of 1.3- and 1.5-inches.
However, people who have already started queuing for Apple’s iPhone 6 face a wait of two weeks after reports claim the device will go on sale a fortnight from today.
Although Apple is set to unveil its iPhone 6 at an event next Tuesday, it is unlikely to go on sale until the following week.
Traditionally, Apple announces a product on a Tuesday before releasing it ten days later, on a Friday, which this year falls on 19 September.
Since 2012, Apple has scheduled an iPhone event midweek in September, released the latest software update the following Wednesday, and then released the devices the Friday after.
People began queuing outside the Fifth Avenue Apple Store on Wednesday, hoping to be the first to get their hands on whatever new devices Apple unveils.
Camping outside stores has become a tradition, but this year the camping has started more than two weeks early.
In addition to new iPhones, Apple could launch new versions of its iPads along with new iPhones and the iWatch next week.
The same report predicts that the iPad Air 2 will be announced on the same day as the iPhone 6 rather than in a separate event in October.
Experts claim the new iPad 2 Air will feature a fingerprint sensor and a new thinner design.
The event will be held at the Flint Center for the Performing Arts at De Anza College in Cupertino, the same location where Steve Jobs introduced the original Mac 30 years ago.