The largest recorded pitcher of "N. rajah", measuring 41 cm, was found on March 26, 2011, during a trip to Mesilau organised by The Sabah Society. The trap was discovered next to a steep sidepath of the Mesilau nature trail and was measured by Alex Lamb, son of Anthea Phillipps and Anthony Lamb, who were also on the trip. It was collected for preservation at Mesilau Headquarters. Another trap measuring 40 cm was spotted on the same day. The previous record for a "N. rajah" pitcher was 38 cm.