I can see from your first picture that you need to Remove Doubles along the seam to remove it.
What object did you use as a base? You could probably do with temporarily blanking out the specular and normal map textures to make sure the mesh issue is corrected first as it will be easier to see.
In Edit Mode click on the button that is four icons to the right of the word "Global" on the bar just under the 3D viewport. This makes sure that you can select all the vertices that are needed.
Then set vertex selection active (the icon that looks like a little box with an orange dot in the corner)
Press B on your keyboard and drag a little box around the vertices along the seam on the mesh. Make sure you only select the vertices along the seam. You might have to move the camera angle to make sure you don't grab any extra ones. If you do, just Ctrl Z and try again. Each time you press B and draw a box selection it should add to what is already selected.
When the whole seam line is selected, go to the Mesh Tools bar on the left of the screen and scroll down until you see a Remove Doubles option. Then click it.
If I've explained well enough and you have managed to follow this then the seam should vanish and a little message will appear at the very top of the screen telling you how many vertices have been removed.
Import your edited mesh back into studio and check how it looks in the game.