July 2015 : We four authors (Fabio, Alex, Haris and Mark) have submitted a paper in July 2015 and transfer of copyrights to the Journal A. Alex was corresponding author and I am Mark the 4th author.
October 2015: The paper got accepted and published also appeared online.
June 2016: I suddenly came to know through Google search that same article has also been published by three authors (Fabio, Haris and David) in December/January 2016 in Journal B. Fabio is corresponding author, I was not aware of this and also I am not an author in this duplicate publication.
At the time of submission in July 2015, as per my knowledge this paper was not submitted/or being published anywhere else.
This duplicate publication was accepted in December 2015 and appeared online on January 2016 in Journal B
In this whole situation being the 4th author in the first publication (Published in Oct 2015 in Journal A) where do I stand ? Are authors of duplicate publication guilty of plagiarism or copyrights violation ?
What are suggestions for me ? What should I do ? Does it all effect my authorship ?