Tirupati, Sept 8 (PTI) Four New Delhi bound passengersdetained for questioning over suspicious liquid pain killerbottles found in their baggage at nearby Renigunta airportwere let off today, a senior police official said. Renigunta Deputy Superintendent of Police K S Nanjundappatold media persons that the forensic lab where the samples ofpain killer test was sent certified that the medicine wasnot dangerous. The four, who were to board a flight to New Delhi, weredetained yesterday after the pain balm showed traces ofinflammable content during security check. PTI COR APRRGDK