The manager of the Nauti and Nice adult stores admitted at an inquest into the death of truck driver Glenn Punch that it was a ‘‘commercial decision’’ to keep selling the so-called legal highs after reading in Newcastle newspapers almost every day that they were ‘‘legal but lethal’’.

‘‘The profit motive was too big,’’ said Mathew Wynn, who added that synthetic drugs became such a scourge in the Hunter Region that ‘‘everyone was selling it’’  before  Mr Punch’s death.

A shop assistant, Jessica Cox, said one store would sell about $7000-$8000 worth of synthetic drugs a day and managers encouraged staff to try it so they knew what they were selling, a claim Mr Wynn strongly denied.

She said one woman who regularly bought synthetic amphetamines, or bath salts, asked if she could eat Ms Cox’s face off.

She then saw her walk out of the store and eat a dead animal off the road.

Another shop assistant, Cameron McEwan, said staff were given no advice on how to sell the products – which comprised 60-80per cent of sales – and he used his own knowledge or feedback from other customers to tell them it could be smoked, snorted or injected.

Mr Punch, 44, and his girlfriend, Rachael Hickel, purchased a bath salts product called Smokin Slurrie from the Rutherford store and injected themselves in the back of their truck on October21, 2012.

Mr Punch jumped the barbed-wire fence of a nearby shipping yard on the Newcastle outskirts, smashed a window in a psychotic fit and went into cardiac arrest when  security guards restrained him.

Ms Hickel had such intense hallucinations from the drug that she thought she saw him drive off in a car while she was screaming for help, covered in blood after falling from the prime mover.

‘‘I thought it was all fake, even at the funeral,’’ she told the Sydney Coroner’s Court.

It was the fifth time they had tried Smokin Slurrie and each time, Ms Hickel had flushed the rest down the toilet because it made her partner strip off and behave strangely and gave her terrifying hallucinations that lasted for up to six months.

Gregory James, QC, representing Nauti and Nice, asked why they still took it when it had such effects and when Ms Hickel used anti-depressants.

‘‘I can’t answer that question,’’ she said. ‘‘It’s stupid, I know.’’

Mr Wynn said he never investigated the health impacts or the legality of the products because there were stories in local newspapers everyday saying it was ‘‘legal but lethal’’.

He was also given letters by law firm Northside Law, written on behalf of the distributor  of Smokin Slurrie vouching for the product’s legality.

Asked by counsel assisting the coroner, Peter Hamill, SC, why he sold the products if he knew it was lethal, he said: ‘‘Everyone in the area was selling it.’’

‘‘[And you were] turning a very healthy profit?’’ asked Mr Hamill.

‘‘That would be correct,’’ he said.

He took Smokin Slurrie and all bath salts off the shelves when Mr Punch died.

Police testing later revealed that the drug’s active ingredient was Alpha-PVP, a substance that is an ‘‘analogue’’ of a prohibited substance, making it illegal.

Alpha-PVP has since been outlawed after sweeping changes to synthetic drug legislation in NSW.

The inquest continues.