Unwilling witness

I am being forced to be a witness for both sides of a case where an employee is suing the company for firing him because he believes of his ethnicity and faith. Now both are calling me as a witness because I am the same as him. One wants to use me to say look we did not fire him and the other thinks I know more than I do. I do not even know this guy and have no reason to believe he was fired for anything remotely connected to ethnicity or religion. I think forcing me to be a witness is a form of discrimination, but I don't know what to do. Need feedback.