Dear friend,
There is no mention in the post of what the duration of the probation period was and whether the employee was officially confirmed in the post for which he was selected or was undergoing probation before the termination based on background verification. If he was only a probationer, the action of the management in terminating his services based on any negative feedback in the background verification report without assigning any reason or notice as per the terms of the contract of employment might be correct. If not, the management ought to have at least mentioned the reason for the termination in the orders, as it can be construed as a declaration to the effect that the individual was never appointed since he has procured the appointment by means of submission of fake documents or suppression of certain vital facts, as the case may be, and not an order of termination in the normal sense.
Coming to the issue of withholding 45 days' salary out of a total of 75 days of service, it is certainly illegal. Salary is the compensation payable for the services rendered. Hence, it is the automatic right acquired by the employee for remaining under the services of the employer subject to his directions and disposal. Thus, salary is first earned by the employee and only then becomes payable, resulting in the fulfillment of the mutual consideration of the contract of employment. Therefore, the employer has no right to withhold the salary for the duty period.