The 14 year old suspect, who was also a pupil at the school, was arrested at midday on Thursday, an hour after a body was found in a park in the town. The body has not been formally identified but police said there was a "strong possibility" it was linked to the arrest.
Superintendent peter scofield said: "that is a strong line of inquiry we are pursuing but until the body is identified we can't say any more." He said he did not anticipate further arrests  being made in connection with the discovery of the body.