"We knew the jury had been struggling, they'd been out since Friday, they had the weekend, they came back yesterday and I think it became apparent that the possibility of a hung jury was a real one.
"There will be a retrial -- that could be in a matter of a couple of months, but depending on the court's schedule, that could be into early next year now," Mr Wilkinson-Smith said.
"If one jury can't make a decision we try again, if two juries can't, well then it becomes an issue as to whether there should be a third trial."
In September 2011 Leaitua, his partner, two children and mother-in-law Sorlinda Aristizabal Vega flew from Argentina to Auckland.
Ms Aristizabal, 37, a Colombian national, had 584 grams of cocaine in condoms inside her body, and she died of an overdose of the class A drug the day after landing.
Three of the 27 condoms had broken inside her intestines, causing cocaine to fatally leach into her system.
Leaitua's defence lawyer Chris Wilkinson-Smith argued Ms Vegas was acting alone and Leaitua wasn't involved in his mother-in-law's smuggling.
Leaitua has been remanded on bail.