Nokia Australia is under investigation by the Australian Communications and Media Authority over alleged breaches of the Spam Act.
"We have been contact by ACMA and we will assist them with its enquiry," a Nokia spokesman confirmed to iTnews.
The formal investigation, understood to have been in the pipeline some six weeks, follows at least one complaint alleging difficulties unsubscribing from an SMS "tips and special offers" service run by the handset maker.
The tips allegedly include: "Tip: Listen to music in stereo sound and manage your calls with the Nokia Stereo Headset WH-500. Visit [...]" and "Tip: Use less battery power and help conserve energy with a few helpful tips from Nokia. Visit [...] to learn more."
Affected users allege the messages are sent on the basis of their mobile number - following them even after they give up their Nokia handsets.
One of those affected is Victorian open source business solutions consultant Dave Hall although global Nokia message boards hosted similar tales from other users.
Hall told iTnews that other users impacted have been in contact with him directly.
He said the SMS messages were initially classed by ACMA as "factual services messages from a company I have a relationship with" but that "after being pushed they realised they're not just informational messages and have decided to take action."
The only ways to unsubscribe from the service are either in the phone menu of the Nokia (assuming the user is still using the device) or by "really scratching around on the internet" for instructions, Hall said.
It is allegedly possible to unsubscribe by signing up to the My Nokia service - but that requires details including full name, date of birth and contacts to be registered in order to access an unsubscribe mechanism.
Although officially now "unsubscribed", Hall received another message from Nokia last week.
"I'm not getting them as frequently, but I'm still getting them," Hall said.
"The whole thing seems to be set up such that they don't want to let you go. I've spoken to several other people who have had real trouble [with the service] too."
Hall believed the saga had damaged Nokia's brand.
"As things stand now, I am not feeling like recommending Nokia to family, friends or clients. Instead I am more likely tell this story and discuss the lack of customer service," he said in a blog post.
Nokia's spokesman did not elaborate on the handset maker's planned defence of the allegations, nor did it respond to queries on why it had allowed the issue to escalate to the point of a formal investigation.
ACMA did not respond to a request for comment by the time of publication.