An Air Carrier crew descending into Freeport at 7;000' climbed 500' in response to opposite direction VFR traffic on the airway when it generated a TCAS TA. Freeport ATC has no radar.

Narrative

While descending into Freeport on BR62V heading toward the JAKEL intersection we were descending to 7000 feet when were informed that radar services were terminated and to contact Freeport Approach. After contacting Approach we noticed traffic on TCAS that was opposite direction and indicating 6800ft on the airway. We queried ATC about the traffic and; as they had no radar coverage; they did not know of the traffic and said he was probably VFR. Since we were opposite direction and approaching each other rapidly I made the decision to start a slow climb as we had just received a TA and an RA was imminent. We informed ATC of the climb and they told us to report clear of the traffic. I climbed a total of 500 feet to avoid a conflict and we eventually got a visual on the traffic. Once visually clear of the traffic I slowly started a descent back to 7000 feet and received a 'MONITOR VERTICAL SPEED' RA however my descent rate was within the green band on the VSI. Since Freeport has no radar coverage we had no prior warning of the VFR traffic flying on our airway. Without the TCAS it would have been very difficult to spot the aircraft until we were dangerously close. The VFR traffic was flying on the centerline and either had an incorrect altimeter setting and/or did not hold altitude very well. Not much can be done to prevent VFR traffic from flying; however when flying into uncontrolled airports or those without radar coverage we should not be allowed to MEL the TCAS. We could have had a very serious incident with the VFR traffic had we not been TCAS equipped.