An unlicensed learner driver recorded an alleged blood alcohol reading of 0.319 - one of the highest on record.
The 23-year-old man was detected at an alcohol and drug testing site on Fitzgerald Road in Laverton North at about 9.45pm on Wednesday.
His vehicle was immediately impounded for 30 days.
The man, from Truganina, is expected to be charged on summons with drink driving and other traffic related offences.
He was also arrested over an outstanding warrant and later released on bail.
Learner drivers must have a zero blood alcohol reading.
Quotes attributable to Acting Superintendent Randy Anderson, Road Policing Command:
"Driving a vehicle requires a high degree of attention and vigilance.
"That's why police are so steadfast on removing drink drivers from our roads.
"Be it a booze bus on the roadside or a police car in your rearview mirror - you never know when and where we'll be testing to keep all road users safe."
