The victim lodged an FIR against the duo at Vakola police station yesterday alleging that the incident occurred on the night of August 16 after he had hired the service of the callgirl through an agent, said senior inspector M Vavhale.
As soon as the girl arrived at the spot along with her driver, the latter threatened the 40-year-old complainant with knife and demanded cash, police said.
He handed over around Rs 1.5 lakh in cash to the accused who fled from the spot along with the girl, police said.