In "The Telephone Gambit: Chasing Alexander Graham Bell's Secret," journalist Seth Shulman argues that Bell — aided by aggressive lawyers and a corrupt patent examiner — got an improper peek at patent documents Gray had filed, and that Bell was erroneously credited with filing first.
Readers of IPBiz may be familiar with some of the questionable omissions of Shulman in a previous book on the Wright Brothers.
See "Unlocking the Sky": missing a few facts?
For smoking guns, the AP story notes:
As Bell described that new approach, he sketched a diagram of a person speaking into a device. Gray's patent documents, which describe a similar technique, also feature a very similar diagram.
Shulman's book, due out Jan. 7, recounts other elements that have piqued researchers' suspicions. For instance, Bell's transmitter design appears hastily written in the margin of his patent; Bell was nervous about demonstrating his device with Gray present; Bell resisted testifying in an 1878 lawsuit probing this question; and Bell, as if ashamed, quickly distanced himself from the telephone monopoly bearing his name.
The story of Bell, Gray, and Meucci is an old one, and may be found at many places on the internet.
One could start here-->
Bell's notebook is on the internet.
Elsewhere, IPBiz questioned Bell's role in creating, and awarding, the Langley Prize to the Wright Brothers, which was the forerunner of giving an Edison Prize to Tesla.