Rumors about Amazon’s reported Kindle smartphone have started gaining momentum. The most recent volley of rumors about the potential kindle phone the online retailer has started testing the phone.

According to a recent report by Wall Street Journal (WSJ), Amazon is working with its Asian hardware suppliers to test a smartphone which may hit store shelves towards the end of 2012 or in early next year.

Citing unnamed sources, the WSJ reported that the phone would feature a screen measuring in the range of four to five inches. A 4-5-inch screen has become the new standard in smartphones. While Apple’s iPhone features a 4-inch display, Samsung's Galaxy S III comes equipped with a 4.8-inch screen.

The online retailer turned down a request for comment on the WSJ report about the potential Kindle phone.

Currently, Amazon is selling Kindle e-readers and tablets. Reports suggest that the second-generation Kindle Fire tablet is already under development.

Tech industry analyst Jeff Kagan recently wrote ina note, "Amazon. com has much of what it takes to be successful. The big question, is can they be successful in the wireless phone business?"

Rumors of a smartphone by Amazon have long been swirling around the Web. Late last year, Citigroup analyst Mark Mahaney predicted that the online retailer would launch a phone of its own in final quarter of 2012, with a price tag of between $150 and $170. At the time, Mahaney also said that the Kindle phone would be developed by Foxconn International Holdings.