Two policemen from Besson Street Police Station in Port of Spain and a 24-year-old El Socorro man remain in custody after their arrest by the South Western Division Task Force on Tuesday.
The three are being interrogated by the Organised Crime Narcotics and Firearms Bureau.
They were detained by South Western Task Force officers after a chase from Cedros to Rousillac on Tuesday.
The officers, led by Sgt Shaeed Ali, report finding four crocus bags containing marijuana, three guns, ammunition and bottles of alcohol in the marked Nissan Xtrail police vehicle.
It is alleged the two policemen told senior officers they were leaving Besson Street Police Station on Tuesday to go on enquiries.