Kharat and Veer were booked under IPC sections 392 (robbery) and 341 (wrongful restraint) and further probe was on.
In the incident that happened in Mankoli area under Narpoli police station limits in the intervening night of May 8-9, several policemen suffered injuries.
The victim received injuries and fell unconscious, he said, adding that the accused left him there, locked the premises and fled.
The four accused who were arrested on April 11 were working as pharmacists at various medical shops in Thane.
The accused Ravindra Sharma was brought to the police station by residents where a case under section 377 of the IPC and POCSO Act was registered.
With a total of 7,833 cases successfully solved out of the total 12,439 crimes registered in2018, the detection rate is said to have increased from 58 per cent in 2017.