Office incharge has power to send me for medical fitness test?

After 25 days of joining duty from Medical leave of 35 days can my office incharge has power to send me for medical fitness test towards medical board and asking about about my truthfulness of illness?
I have taken medical leave from 28 Feb to 3 April
And I joined on 4 April. My office send for fitness test on 2 & 3 May for medical test

Dear Sanyo,
Yes, your company has all rights to get you through Medical Checkup.

Dear Mr Sanyog, have you submitted your medical Certificate & Fitness Certificate issued by a Registered Medical Practitioner? if there is reasonable doubt about your illness & certificate Submitted, Employer can send you for Examination to Independent medical Board to find out veracity of your illness/MedicalCertificates

Are you working in Govt. controlled institution? They normally refer to Medical Board for fitness as per rules.