Last month, the Scot said he wanted to clean up his act after repeated warnings for unsavoury language, but audible obscenities have been uttered in his opening matches in Brisbane against Australia's John Millman and Uzbekistan's Denis Istomin.
Spectators at the Pat Rafter Arena have clearly heard Murray barking the occasional swear word, something the world No.3 has done throughout his career to let off steam when dissatisfied with his own performance.
He defeated Istomin 6-4, 7-6 this morning to book a semi-final against Japan's Kei Nishikori, who trumped Ukraine's Alexandr Dolgopolov by an identical scoreline.
"Obviously me swearing or whatever is bad and wrong, and it's something I want to try to stop doing," Murray was quoted as saying last month.
However, he declined to make the same promise ahead of his clash against Nishikori.
"I don't really know how that will go, to be honest," Murray said.
"A lot of times I get asked after matches about it. It can get picked up on the microphone or whatever.
"No-one has mentioned anything to me yet but the microphones at the Aussie Open are all around the court, so we'll see."
Murray denied his attempt to tone down his language was because he felt more of a role model after winning the Olympics and US Open in a breakthrough 2012.
"Where it (the pledge to stop swearing) came from was when I got asked a question," he said.
"I was doing an interview over the phone. I got asked about swearing on the court. I said 'I don't mean to do it. I don't want to do it. Sometimes you get frustrated and you do and obviously I will try to stop'.
"I didn't make any promises or guarantees.
"So where I would obviously love to stop doing it, I try not to. But I can't guarantee it."