Dias, part of almost all environment protection movements in the coastal state, was found dead in river Mandovi at his village near here onNovember 6.
A section of people reportedly had suspected that he was murdered.
"We have received the DNA report from CFSL Hyderabad. No blood has been found from any of the exhibit sent," Superintendent of Police (Crime Branch) Karthik Kashyap said here.
He said the red marks found on his clothes were not blood stains.
Dias was last seen with two minors who were earlier questioned by the Crime Branch.