A New Zealander has been jailed in Western Australia, after pleading guilty to killing a young surfer while drug-driving

37 year old truck driver Andrew Jon Simon had methamphetamines and cannabis in his system when he crashed into 20-year-old Lachlan Yeo and girlfriend Annie Riley in September last year.

Riley survived the crash but was seriously injured.

Simon claimed he hadn't taken meth that day, but the judge described him a high-functioning user.

And the prosecutor says after the crash, Simon was found with drugs, and was caught speeding and driving an unlicensed car with false plates... despite his license being suspended.

The New Zealander will be eligible for parole after serving four years and his licence will be disqualified for five years after release.