I am currently taking accutane 40mg every two days. I have acne scars & pigmentation, can I start laser to remove scarring?

You need to be off of the Accutane for at least 6-12 months before doing most types of laser treatment. This is especially true for the deeper ablative procedures such as CO2 or erbium.  With the fractionated lasers you might be able to do sooner, but probably not worth the risk.  The non-ablative could be done at 6 months as these do not remove the skin surface.  And the non-ablative work very well for acne scarring.  

My advice will be to postpone any ablative laser treatment for acne scars until you have been off the Accutane for at least 6 months to prevent risks of bad scarring.

No. By no means. During treatment with Accutane, your doctor must have tell that you should not make any treatment laser, peeling or cualquir other than is not justified need. The risk of complications is high.