Kept in a biscuit carton, the pangolin was being smuggled to Bangladesh via Siliguri, police informed on Friday.
A vehicle bearing Bhutanese registration has also been seized by the police.
The identity and details about the five arrested have not been revealed due to security reasons.
Police informed that the five men are part of an international wildlife smuggling racket.
Police produced the five at the Chief Judicial Magistrate Court in Jalpaiguri and two have been remanded to police custody and the remaining three to Judicial custody.
Later, the Pangolin was released in the Bengal Safari in Siliguri.
Pangolins’ scales and flesh fetch high amounts in the international markets hence they are highly vulnerable to poaching.