Hundreds of police officers raided 57 homes of suspected drug dealers in Modi'in, Ramle, and Lod on Tuesday after nine-month-long undercover investigation made possible by a criminology student who acted as a covert police agent.
Forty eight people were arrested so far, including minors - the majority in Modi'in - on suspicion of selling a range of narcotics, and five vehicles were impounded.
The undercover agent, who studying for an MA in criminology, was recruited to the police on Tuesday when the investigation became overt.
Her alleged narcotics purchases were videotaped by back-up officers.
The operation was led by Central police district head Cmdr. Bentsi Sao, who said, "57 criminals... woke up to the sounds of knocks on the door by the Israel Police."
An hour before the raids, the agent took part in an awards ceremony attended by her parents.