New Zealand vs Australia 2016: Skipper Smith pledges to improve behaviour

Australia skipper Steve Smith, who was fined after pleading guilty to a charge of dissent, accepted that he needs to improve his behaviour in the wake of the ugly incident which marred the visitors' return to the top of the longest format of the game after winning the series 2-0 against New Zealand in Christchurch.

Smith was fined 30 percent of his match fee by the International Cricket Council (ICC) for a heated exchange with on-field umpire Ranmore Martinesz in the second Test.

Smith pleaded guilty following their seven-wicket win at the Hagley Oval with ICC determining the Australia captain broke its Code of Conduct by "showing dissent at an umpire's decision during an international match."

"I thought I was well within my rights to go up to the umpire and ask him why we didn't use the real time snicko. I guess out on the field we couldn't really see a hot spot and I've been informed since then, at the (lunch) break just after the incident, that if there is a hot spot they don't go to real time snicko," Smith was quoted as saying by Cricket Australia on Tuesday.

Need to be better as a leader: Smith

"So that was basically what I was doing at the time and that's deemed to be dissent and I'll cop that on the chin. I need to be better as a leader. I need to set the example, and that wasn't good enough I guess."

The incident happened in the final over before lunch on Day 4 when third umpire Richard Illingworth confirmed Martinesz's not out ruling to an lbw appeal against Kiwi batsman Kane Williamson. Smith called for a review when Martinesz turned down the Australian's appeal, with hot spot indicating the batsman had edged the ball onto his pad.

Smith said he felt it was within his rights as the Australian captain to query why the third umpire had not used the real time snicko technology available to him.

Following the third umpire's ruling, the stump microphone at the non-striker's end caught fast bowler Josh Hazlewood swearing when venting his frustration while Smith was also animated, shaking his head and turning away after querying Martinesz on the decision.

"We want to play a tough, aggressive brand of cricket and we know there's a line that we shouldn't cross and Josh probably crossed that line," the 26-year-old said.

"I've also just been fined as well so that's disappointing. I'm the leader of this team. For me, it was about questioning the umpire and the process of what was happening. I've been fined and I've got to set a better example as the leader of this team."