Charged Official Absconding

A Major penalty has been initiated against a Central Govt Employee. Inquiry Officer has been appointed and he has sent notice for preliminary hearing to his official address as registered AD post with copy to his controlling officer to relieve him to attend the hearing.But the official has not accepted the notice and it was returned by the postal authorities as the official was not present in the office. As the official was on authorised absent since past few days, the controlling officer forwarded his copy to the residential address of the charged Official directing him to attend the hearing. If the charged Official were not attended the inquiry, what course of action may be taken from the part of Inquiry officer for further proceedings