Police said the 53-year-old was found unresponsive about 4.50pm today in a cell at western Sydney’s Silverwater Correctional Complex.
Corrective Services personnel and paramedics were unable to revive him.
Griffin’s death was initially labelled a drowning by police after her partially submerged body was discovered in Erina Creek on the NSW Central Coast on the afternoon of March 24.
After initially not finding any suspicious circumstances surrounding her death, a homicide investigation was launched following a tip-off from the public.
Police sent out an appeal for information last week along with a photo allegedly showing Torrens near Hotel Gosford, around the time Griffin left her friends and began walking towards Terrigal, about 2am.
Authorities were working off the theory Torrens followed Griffin, who he didn’t know, from the pub before assaulting her and the teen drowned as a result.
Police said Torrens’ DNA was found under Griffin’s fingernails and that a witness heard a high-pitched scream in the area around 3am.
He was later arrested and charged with Griffin’s murder.
The turn of events left her family, friends and community shocked.
Torrens, from Milsons Point in Sydney, was due to face court again in June.
Instead, police have commenced an investigation but the man’s death is not being treated as suspicious.
Authorities will prepare a report for the coroner.
Readers seeking support can contact Lifeline on 13 11 14 or beyond blue on 1300 22 4636.