Dear Nitu,
In the absence of any solid proof, the management cannot blame any employee unless someone has seen that a cell phone was picked by any particular individual and failed to inform the HR or management.
In this particular instance, the HR can only send out a circular or mailer requesting all employees to report/deposit the cell phone in case anyone has seen/found it.
How can the employee be sure that he has forgotten the cell phone at the office and has not dropped it outside the premises on his way? Is there anyone who has seen the cellphone after the employee has left for vacation? Also, if he was given a corporate number, you can request the service provider to furnish you with the details of the last calls made from that cell phone and the locations from where they were made. This will give you an idea of the area where the phone was last active.
That employee should have noticed the missing cellphone before going out of the city, so why didn't he inform the HR at that time?
You need to discuss this with the senior management to determine if they feel it was the management's responsibility and if the management would provide the employee with another cell phone at office expenses. Also, you need to consider that if the management purchases a new cell phone and gives it to that employee, then in the future, anyone who has lost their cell phone even outside the office premises will demand a new phone, claiming that it was left on the desk and stolen.
For the future, you have to create a circular and include in the policy that all employees are responsible for their personal belongings. Any kind of valuables should not be left at the office, and if it is mandatory, they should be properly locked away.
Also, if the management approves, you can have CCTV cameras installed on the premises. You can justify to the management that it will also help in keeping track of employees who are frequently absent from their seats, ensuring more productivity.
You can educate employees, admins, security staff, office boys, and housekeeping to report if they see any cellphone unattended.
Hope this will be of some help.
Warm regards,
Sourabh