This is the case of abandonment of employment. Follow the following procedure:
a) Send a notice to his last known address on his unauthorised absence.
b) If the absconding employee fails to report for his duties then order domestic enquiry. If the absconding employee fails to depose before the enquiry, order the enquiry for the second time. Send the communication to him through Registered Post and retain the office records properly.
c) If the employee fails to depose the enquiry even for the second time also then your management can take ex parte decision to remove his name from the rolls of the company.
d) If the employee is in possession of the company property like a laptop, mobile phone etc then while sending the notices, direct him to return the company property.
e) If the employee fails to return the company property then lodge a police complaint. However, you should have sufficient evidence of the transfer of the property from the company to the individual.