Australian Nick Kyrgios has been slugged with a $US3000 ($A4340) fine for uttering an audible obscenity in his opening-round victory over Spaniard Pablo Carreno Busta at the Australian Open.

The incident occurred early in the second set of Monday night’s straight-sets victory over Carreno Busta.

Kyrgios takes on Uruguayan Pablo Cuevas on Wednesday night in the second round at Melbourne Park.

Had the incident happened at a regular ATP event – rather than a slam – Kyrgios would be perilously close to triggering a 28-day ban.

The Australian still has a suspended sentence hanging over his head after being sanctioned for sledging French Open champion Stan Wawrinka in August at the Montreal Masters.

The 28-day suspended ban would be triggered if he received further fines totalling $US5000 ($A6840) before February 24.

He was docked $US1500 ($A2170) for another audible obscenity late last year in Shanghai.

But Wednesday’s fine does not count towards the total as it happened at a major.