Unwanted artifact in render

I am doing my test renders and in one of them, the camera zooms in on a character and at one point this random artifact shows up right in front of his neck. I did two renders and both show the same thing.
What gives? Can anyone help explain troubleshooting for cleaning up random artifacts that show up in a render?

Edit: I used avi.jpg and right now I am trying to use another avi raw. Maybe that was the problem, I will let you know soon.

Edit: avi.raw did not fix the issue.

Could we have a render in which said artifact is visible?

Update: After rotating and doing some frame by frame renders, I feel quite foolish since I have come to realize that the artifact is not in fact an artifact. It happens to be an odd deformation in the neck of one vert and the way the light reflects makes it look out of place. It happens so fast and randomly that it appeared to be an artifact.
I have to figure out how to fix that since it does not happen during pose mode and only during render.
So my suggestion to those who have my problem, first go to the area where it happens, render a still image and review. Then step a frame or two, render image and review. Soon you will figure out where it happens and what it probably is.
I did that and looked at the model from different angles in the 3d window to pin point the problem.