With screens of 4.7 inches (11.9 cm) and 5.5 inches (14 cm), the two new models would be Apple's largest iPhones, the person said.

The new handsets are still in development and plans haven't been completed, a source said citing the person, adding Apple probably would release them in the third quarter of 2014.

Natalie Kerris, a spokeswoman for the Cupertino, California-based technology company, declined to comment.