Investigation Questions
This is in addition to what Mr. Nathrao has said. Consider the following questions for the investigation:
a) What is the designation of the employee, and in what capacity did he work?
b) What was the nature of the financial transaction? Who paid the money? Why did the payer not find it irregular to transfer funds to the employee's personal account? Was the employee authorized to be involved in financial transactions?
c) For the financial transaction that has taken place, is there a Standard Operating Procedure (SOP) well in place? Did the employee violate the SOP? If there is no SOP, are there written orders on how to handle money transactions?
d) Who discovered this financial transaction? What was the time gap? In exchange for the money, did the employee provide any material to the payer? If yes, was there a shortage of material detected?
e) Did the Head of Department (HOD) or the employee's Manager discover this anomaly? If not, why did it escape their attention?
f) Did you call the employee and ask for a verbal explanation? What was their defense? What is the level of credibility of their explanation?
About Legal Action
Far from disciplinary action, you wanted to take "legal" action. Nevertheless, if you do not have a laid-down procedure on how to handle financial transactions, then I doubt whether you can take any action. To take action against the employee, blameworthiness must be clearly established as to which rule or regulation the employee has violated. Yes, all company-related transactions must take place through the company's account, and it is wrong to transfer funds to one's personal account. However, without laid-down rules, the law does not recognize "wrongness."
Thanks,
Dinesh Divekar