Dear (Name of the person),
This is to bring to your kind notice that our most confidential data has been stolen under your supervision. It was not at all expected from any employee of the company. We have decided to terminate your employment with the company and this decision will not be changed at any cost. You are supposed to reach the office early tomorrow morning and report yourself in the office. It was the most shameful thing that ever happened in our company.
It is also decided by the committee that you will not receive the paycheck for the last 90 days as you were not loyal and committed to the company. You will also not get extra perks for this month. You have broken our trust which we have kept on you. We should not appoint you at our confidential places. The data which is stolen was extremely important for us. We got it after so much effort and time. It cannot be recovered from the system. This thing is unavoidable and we have also taken our final decision.
I hope that you will reach us on time tomorrow and also bring all the important documents which we have given you at the time of joining. You are advised to take all your belongings from your desk and also leave as early as possible. You can ask us if there is any query regarding our decisions.