In the case of grave external scandal or of most grave imminent harm to the institute, a member can be expelled immediately from a religious house by the major superior or, if there is danger in delay, by the local superior with the consent of the council. If it is necessary, the major superior is to take care to begin a process of dismissal according to the norm of law or is to refer the matter to the Apostolic See.
Source: Code of Canon Law (Vatican.va)