Abstract: A secure specimen collection vessel is provided, which in a preferred embodiment comprises a four-chamber base cup, 1, a twist-lock antirotation cap, 2, and a resilient sealing plug, 3. Clip-off drain tabs, 6, and vent tabs, 7, are located at the bottom end of the base cup, allowing each chamber to be drained individually for repeat analysis of a urine sample. The locking, antirotation cap, 2, prevents the contents of the vessel from being accidentally contaminated by the external environment, and also assures that any attempt to forceably remove the cap, 2, will result in visibly obvious damage to the collection vessel.