It is normal for the investigation to include your information about what happened. It is part of what your "cooperation" clause in your policy requires. Read your policy for your exact language.
You must cooperate with them under the policy. There purpose in all of this to determine if you caused/allowed the loss in the first place. They will dig deeply in order to avoid paying you.
Both my colleagues have responded with good counsel. I only add that you should retain counsel to go with you to the exam under oath, to be as friendly and cooperative as possible. Good luck.