PEOPLE in Wagga are legally obtaining the powerful painkiller fentanyl for $6 a skin patch and on-selling it to abusers of the drug for $200, an inquest has been told.

The revelation came during an inquest into the death of 38-year-old Shayne Barker, who was found dead on a bathroom floor hours after he and another man paid $30 each for a quarter of a patch and then halved it.

The abuse of fentanyl has claimed scores of lives across Australia in recent years and there is growing alarm about its illegal use in Wagga and the toll it is taking on opiate drug users.

The inquest will determine Mr Barker's cause of death, but coroner Michael Antrum was told on Friday a toxicology report indicated the level of fentanyl in Mr Barker's body at the time of his demise on December 13 last year overlapped the therapeutic and lethal range.

The inquest heard Mr Barker was a regular fentanyl user and typically injected the drug into his ankle after extracting it from patches.

Yet no needle or patch was found near Mr Barker's body by police who were called to the Meurant Avenue house in which Mr Barker rented a room.

Mr Antrum said the reason he was holding the inquiry was because there were certain aspects about Mr Barker's death that were not resolved in the brief of evidence before him.

The police officer in charge of investigating Mr Barker's death, Detective Senior Constable Daniel Galvin, said from the witness box it was strange no needle or patch was found near the body.

The inquest heard another person had died in the house from a drug overdose six months before Mr Barker's death.

"From my experience, that stood out as a bit odd," Detective Galvin said.

The man who shared the house with Mr Barker, John Clear, denied to police at the time of Mr Barker's death that he had interfered with the scene.

In the witness box on Friday, he again angrily rejected repeated suggestions by Sergeant Steve Watterson, counsel assisting the inquest, that he removed a needle or fentanyl patch after he discovered Mr Barker's body.

"Let's get this straight, there was nothing there," Mr Clear said.

"I did not touch anything."

Mr Clear reported Mr Barker's death by driving to the police station - bypassing the opportunity to make an emergency call on his mobile telephone that had no credit and driving past two hospitals, a service station and at least one public telephone.

"That is not adding up, Mr Clear," Sergeant Watterson said.

"I don't know, it was probably the shock of finding him," Mr Clear replied.

The man who shared the fentanyl patch with Mr Barker told the inquest he picked Mr Barker up from Meurant Avenue about 10.30pm on December 12 and they drove to a park in Connorton Street, Ashmont, to buy fentanyl.

The man said Mr Barker got out of the car and bought the quarter patch from a person for $60.

He said full fentanyl patches were being sold to abusers in Wagga for $200 to $250 for a full patch, $120 for half a patch and $60 for quarter of a patch.

The pair halved their quarter patch - effectively getting one-eighth of a patch each - before the man took Mr Barker back to Meurant Avenue and then went to his own house and used his share by placing it under his tongue.

Sergeant Watterson asked the man about the effect the fentanyl had on him that night.

"It was nothing different or anything," the man replied.

"It definitely was not stronger."

The man told the inquest that was why he could not understand how Mr Barker's share could have "taken him down".

The court heard Mr Barker received some money on December 12 and it was possible he might have bought and injected fentanyl that day before his late night purchase.

Mr Antrum will deliver his findings on January 16.

THE Victorian Department of Health says fentanyl is a highly powerful opioid with a small margin between therapeutic dose and toxic dose.

It can only be obtained legally through a prescription issued by a medical practitioner for chronic severe disabling pain not responding to non-narcotic analgesics.

The risk of becoming dependent on fentanyl is high.

"There are a number of risks of overdose from fentanyl patch use," the health department says in a bulletin.

The bulletin says many reports of fentanyl-related deaths from around Australia involve the injection of fentanyl extracted from patches.