Aaron Hernandez reportedly showed no traces of synthetic marijuana "K2" or any other illegal drugs in his system.
The former New England Patriots tight end committed suicide in his prison cell on April 19. He was serving a life sentence for the murder of Odin Lloyd.
WCVB reported on Saturday that toxicology reports showed no trace of any drug in Hernandez's system.
There had been numerous reports suggesting Hernandez had possibly used "K2" prior to killing himself.
The state medical examiner has ruled Hernandezs death as a suicide from asphyxia by hanging.
The prison was put in "lock down" while officers searched it looking for weapons and possible illegal drugs.
WCVB's report said that several homemade weapons and "K2" were found in the search.