It actually works like this:
-- receive sprite as first parameter and event as second
function onTouchBegin(sprite, e)
-- check if event hit this exact sprite
if sprite:hitTestPoint(e.touch.x, e.touch.y) then
-- remove it from the stage
sprite:removeFromParent()
-- also lets not forget about references in actors tables
local body = actors_r[sprite]
actors[body] = nil
actors_r[sprite] = nil
-- and we could either destroy the body here
world:destroyBody(body)
-- or reuse it to attach to the next sprite
end
end