Problem with lighting while working on an vuforia project

Hi,

There is a problem with lighting in my vuforia project. I just placed an object on a marker and added some point and directional light sources in the scene.Now the lightings are just fine but in the play mode when I just move the phone closer to the object the light get covered by something and that particular area gets dark.Is this because of the ARcamera object covers any of the light sources while moving the phone?

I have tried all the usual Unity things but nothing seems to solve the problem.

If anyone else has experienced this or has any tips I would really appreciate some help.

Thanks.