You are in radar at an airfield outside CAS, you have been providing a RAS to an inbound, you have transferred your inbound to tower and you suddenly notice a fast moving unknown going towards the inbound, what do you do?
Pass the traffic information to the tower Controller and leave the decision of what they do between them and the crew of the aircraft - it's not your decision anymore. Flight conditions may be such that the Captain of the aircraft decides to continue with the approach.
As an addition to this thread, when providing a RAS and you clear the aircraft for a visual approach, do you downgrade to a RIS as you are no longer in control of the level?
Normally by the time I clear the aircraft for the visual it'll be from a position that transfer to tower is acceptable, still at a level at or above minimum RAS provision level - so the question never arises.