The arrestees were identified as Md Siraj Matbor, 30, son of Shahid Matbor, Md Musa Khan, 25, son of Shahjahan Khan of Gabbaria village in Patharghata upazila of Barguna, and Md Hakim, 20, son of Abul Kalam of Tafalbari village of the same upazila.
Divisional Forest Officer (DFO) of Sundarbans east zone Md Belayet Hossain said the trio illegally entered the forest to set up deer traps but they were caught by a patrol team of the Forest Department.
Fifty deer traps, a large fishing net and a boat were seized from them, he said.
A case has been filed against the trio under the Wildlife (Conservation and Security) Act, the DFO said.
On November 5, forest officials detained 60 suspected deer poachers while entering the Sundarbans with hunting equipment in three trawlers in Joymoni area of Chandpai Range.
The Sundarbans is a mangrove forest enlisted as UNESCO World Heritage Site is home to unique flora and fauna.