Bright outline on objects rendered
 

Hello,

I have a question about rendering objects in Maya, for compositing in After FX. I'm in Maya 2013, using Vray to render, working on a scene with my models in front of a sky background.

When I import my VRay render in After Effects, I set the Alpha to "Premultiplied/Matted" so as to display the objects alone, but then I have a bright outline on all objects rendered. I have to apply filters in AFX, matte chokers, etc to get rid of it of this outline, which messes with the original edge of the object, especially when it's a small object such as a ladder.

Do you know where this bright outline comes from, and is there a way to render objects without it?

Thanks