The parents of a Brisbane boy lost to drugs at a music festival want pill testing introduced nationwide.

Josh Tam died after taking an unknown substance six months to the day, at the Lost Paradise event on the NSW Central Coast.

Speaking publicly for the first time about the tragedy to 9News, his parents John and Julie are still struggling to come to terms with their loss.

Julie and John Tam have spoken for the first time about their son's death. (9News)

"Wish he could be here physically with us, but I know it's not gonna happen," a teary Mr Tam said.

The coroner found Josh died of a heart attack brought on by the unknown substance, not an overdose.

“Unfortunately he's gone missing for a bit there,” said Josh’s mate, Henry Devine.

Josh Tam died of a heart attack brought on by an unknown substance. (9News)

He, along with Josh and a group of mates had all travelled down to Gosford for the festival. They went looking for him, but it was too late.

“I got a call from a police officer and we'd been told that he'd gotten taken to the Gosford Hospital. We got told that he’d passed away," Henry said.

“Look at what’s happened, we’ve lost one of our best mates from it. In the blink of an eye, our lives have changed,” said another mate Nathan Jennison.

The Tams are calling for pill testing to be introduced nationwide. (9News)

Josh’s parents in no way condone drugs or drug taking, but say parents need to realise you can’t stop some kids taking drugs.

Instead they’ve started ‘Just Mossin,’ an organization aimed at educating young people about what to do should a mate make the unfortunate decision to take drugs.

"One of the things that unfortunately happened for Josh, is he took himself away from his mates,” said Julie Tam.

Josh "went missing" from his friends before he died. (9News)

His parents believe if they'd stayed together, Josh might still be alive today.

“That they drink water and that they look after their mates" was a message Josh's parents were keen to spread at a memorial game day in Ashgrove, held in Josh's honour.

“We've got to find another way to help educate these kids so they understand the dangers of it,” said Mrs Tam.

"If we can save one boy or one girl from dying or taking illegal drugs, we've done our job," added Mr Tam.

A coronial inquest will be held not only into Josh's death in NSW next week, but five other people who died at music festivals across the state over the Christmas/New Year period.

Ahead of that, Josh’s parents have urged the Coroner to introduce pill testing at music festivals right across the country.

"Provide them with a choice whether or not this is a good thing for them," said Julie.

John would like to see harm minimization measures introduced at festivals including cooling down tents, ice buckets, ice baths and free water.

Because Josh’s parents believe something has to change.

"There's not a day that doesn't go by that I don't shed a tear for my son, that's just the reality of it," Mr Tam said.