One device is already in an advanced stage of development, the paper reported, citing a source. However, another source said Amazon may decide not to release it, according to the paper.
The device is likely to be launched in 2014 if Amazon decides to proceed with the project, the newspaper said.
Amazon and HTC could not be immediately reached for comment.
Speculation that Amazon will launch its own mobile devices has been around for years. In 2011, Citigroup said that Amazon would launch a smartphone in 2012 through a partnership with contract cellphone maker Foxconn International.
If Amazon turns to Asia to launch a smartphone, it will be following the example of Google, which tied up with Taiwan's Asus and South Korea's LG Electronics for its Nexus devices.