It's long been rumored that Apple's next-generation iPhone 6 will come in two sizes: one with a 4.7-inch display and another with a 5.5-inch display. Now, an alleged leaked document of what is believed to be a schematic of the iPhone 6 provides further hints that we could see an Apple smartphone in the 5.5-inch range.

As spotted by BGR, a diagram posted on a Chinese website and later popped up on French blog Nowhereelse.fr — which often has a solid track record for getting leaked tech products photos ahead of launches — reveals the dimensions for the iPhone 6, or at least one of the models.

The length is listed at 5.9 inches and the width comes in at 3.3 inches, a significant jump in size over the current iPhone 5S. That model is 4.87 x 2.32 inches.

The size would be make it even larger than the new HTC One, which has a 5-inch display and measures about 5.7 x 2.7 inches. That suggests this model of the new iPhone, if accurate would have a display measuring about 5.5 inches.

Stepping into the 5.5-inch size would represent Apple's first foray into larger handsets, often referred to as "phablets." Samsung kicked off the bigger smartphone market in 2011 when it announced the original 5.3-inch Galaxy Note phone. Other manufacturers such as HTC, Nokia and LG rolled out similar sizes soon after.

Meanwhile, the software that's expected to come with the iPhone 6 is rumored to have better mapping and a strong focus on fitness.

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