While Sony is still struggling to keep its handsets a secret before they get official, it looks like a new handset is on the loose, which according to XDA Developers forum user that goes by the nickname iRimas bears the model number Xperia D6503.
iRimas shared an entire photo gallery of the Xperia D6503. The smartphone looks a lot like the Xperia Z1 announced last fall (2013) at IFA 2013 by Sony. All the ports and buttons are placed exactly the same as on the Xperia Z1, the only difference that we can spot from these photos is the lanyard positioning on the left corner of the Xperia D6503, instead of the right side as it is on the Xperia Z1.
We are waiting for iRimas to share some promised screenshots of the UI (user interface) of this device.