Kolkata: Netaji Subhas Chandra Bose's grandnephew and researcher Ashish Ray today claimed he has "irrefutable evidence" to prove that Bose died in an air crash in Taipei (Taiwan) on August 18, 1945.Demanding that the ashes in the Renkoji temple should be brought back to India, Ray said, "There are three reports which clearly state that Bose had died in the air crash in 1945 and did not have the opportunity to enter Soviet Union."