A West Auckland man has admitted supplying synthetic drugs in relation to the death of young Henderson father Calum Jones.

West Harbour man Jonathan Gordon, 23, appeared in the Waitakere District Court today and pleaded guilty to a charge of supplying a psychoactive substance.

Jones, 22, died at his family home in Henderson on September 1.

He had been battling an addiction to synthetic drugs for years and had only been home from full-time rehab for one day when he died.

Despite doing better than he had in years and getting on top of his severe addiction, Jones used synthetic drugs shortly before his death.

Last month police charged Gordon with supplying.

He will be sentenced in April.

Jones' parents Lorraine and Lewis and his sister Heather were in court today to see Gordon plead guilty.

They said it was a relief they would not have to endure a trial, and that they could move on with their lives without worrying about a lengthy court process.

"I'm pleased he's taken ownership of his actions," said Jones' mother.

"This is not about destroying his life, it never has been.

"It's about him not putting his - or other - parents through what we have been through with Calum."

On Tuesday the Herald revealed Jones' parents had teamed up with an Auckland MP to push for tougher penalties for those who supply synthetic drugs, which are highly toxic and can be fatal.

Jones is one of at least 25 people believed to have died after using synthetics.

All of the deaths are being investigated for the coroner.

Last week Pakuranga MP Simeon Brown's private member's bill Psychoactive Substances (Increasing Penalty for Supply and Distribution) Amendment Bill was drawn from the ballot and is expected to have its first reading in Parliament by mid-March.

The bill proposes increasing the penalties for those who supply illegal psychoactive drugs to the community from two years to eight years.