The sleuths rescued Nandita Ghosh, assistant teacher of Kalidhan Institution on Southern Avenue, from Sonarpur in South 24-Parganas district after tracking her mobile tower location, it said.
The police arrested the driver of the vehicle, Prasenjit Roy (26), Arpita Kole (33) and Tanushree Paul (27) for their alleged involvement in the abduction.
The police is looking for the fourth person, Tanushree's husband Amit Paul, for his involvement in the crime.
"But Ghosh neither provided his kin any job nor she paid them the money back, following which they planned the abduction," the officer said.
The investigators also found that the teacher had taken loans from several people on behalf of the school after allegedly forging the headmistress' signature.