Chief traffic cop has warned drivers to be aware after a man's blood alcohol reading rose after eating an ice cream.
After a few bites the man recorded a blood alcohol concentration of 0.018.
The experiment took place after the driver applied to Frankston Magistrates' Court to have the interlock device removed from his car.
The prosecutor had queried why the machine had recorded a "fail", which stops the user starting their car.
But the man was adamant he had not been drinking and that the reading was caused by the Bubble O' Bill he had eaten when he stopped at a service station.
Magistrate Rod Crisp told the driver to put his claim to the test by heading across the road to buy one so police could check his story. A police officer conducted a preliminary test that confirmed he was 0.00.
The man consumed part of the icy treat, then police tested him again.
The reading of 0.018 was duly reported back to Mr Crisp, who granted the driver's application to have the device removed.