undercover operation

Translations
операция под прикрытием
The police conducted an undercover operation to catch the drug dealers.
Полиция провела операцию под прикрытием, чтобы поймать наркоторговцев.
Definitions
An undercover operation is a covert activity conducted by law enforcement or intelligence agencies where agents disguise their true identity and purpose to gather information, infiltrate criminal organizations, or observe illegal activities without being detected.