The accused have been identified as Rajkumar Bharti (34) and Ramprakash Tiwari (46), police said.
The complainant's brother was lodged in Mahatma Phule police station in Kalyan, following which he asked Bharti and Tiwari to use their influence with the police and get him released, ACB Thane Police Inspector (PI) Vaishali Pawar said.
The duo demanded Rs 2 lakh as bribe from the complainant to get his brother out of jail, following which he approached ACB, she said.
A case has been registered under relevant sections of Prevention of Corruption Act by MFC police station, she said, adding the duo has been arrested.