Headmaster Nageshwar Rao and superintendent Narasimhalu told the teacher that there was some problem with her caste certificate, and if the vigilance officials found out about it, she would lose her pension benefits.
They asked for Rs 3 lakh to settle the matter.
The teacher, who had served for 35 years, was to retire next year.
After she complained to CBI, a trap was laid and both the headmaster and the office superintendent were caught at her house while accepting Rs 1 lakh in cash and a cheque of Rs 2 lakh, CBI Superintendent of Police V Chandrasekhar told PTI.