A western Sydney pawn shop may hold clues crucial to discovering who killed Monika Chetty who was discovered in bushland with "horrific" chemical burns to most of her body in 2014.
NSW Police believe the qualified nurse and mother of three - who was homeless at the time - was attacked about a week before she was found at a West Hoxton bush reserve on January 3.
The 39-year-old had burns to 80 per cent of her body. Ms Chetty died in Concord Hospital 28 days later.
Detectives believe she didn't seek medical attention and withheld information from police out of fear of reprisals from her attacker or attackers.
Investigators on Wednesday acted on information from the public and searched a Fairfield pawn shop confiscating two computer hard drives and business records.
Detective Chief Inspector Dean Johnstone says the information suggested Ms Chetty received calls before and after the attack from handsets that were then pawned at the shop.
Her 19-year-old son Daniel earlier in September revealed his family is still traumatised by her death.
"We just want answers," he said while wiping away tears at a Sydney press conference.
"There are no words to explain. It's so brutal. You can't just do that to someone or any living thing."
Det Chief Insp Johnstone - speaking at the same time - said he'd never seen such "horrific" injuries and there was no doubt Ms Chetty was in extreme pain.
Australian Associated Press