Hi,
I presume you question is " employee was sanctioned one day leave and he continued to remain absent for one week without any information "
Leave without any information is a serious misconduct. When employee is not reporting to office without any information, from HR you should take initiative to reach him through his direct contact number primarily. If you were not able to reach him through phone you should try with the alternate emergency contact number. In case if the employee is not reachable @ both numbers then please send a warning letter to him advising him to report back to work. Provide some on or before letter in the date.. before which employee should report back.