The owner of a rogue tyre recycling business at the centre of an ABC investigation has been convicted of threatening a former associate and a former employee by leaving abusive messages on their mobile phones.

Antonio Di Carlo, 46, pleaded guilty in the Beenleigh Magistrates Court to three counts of using a carriage service to threaten to cause serious harm.

He received an 18-month good behaviour bond and a security of $3,000 for all three offences.

Magistrate Michael Driscoll said Di Carlo must take part in counselling to address his anger and quoted from a psychologist's report tendered to the court by the defence:

"In terms of treatment I would recommend Mr Di Carlo continues to engage in psychological interventions, cognitive behaviour therapy including to address your enduring anger, anxiety related difficulties."

In July last year, 7.30 revealed that Di Carlo's Tyremil Operation was stockpiling about 800,000 used tyres at two Brisbane sites, despite the concerns of the environment department and the fire service about the risk of a massive fire.

7.30 was told by company insiders that the two sites at Kingston and Rocklea were dumping grounds for used tyres, with very little recycling at either locations.

The charges were laid over a series of voicemail messages on the mobile phones of a former associate and a former employee, accusing them of speaking to the ABC.

The ABC has obtained one of the voicemails, which stated:

"… You guys want to f**k me over with Tyremil and ABC — I hope you guys don't put any false statements in because not only will I break your f**king legs right but I will sue you for any damage to Tyremil if you put any false statements in."

The court heard that Di Carlo had a criminal history, including of domestic violence and other minor drug offences.

Di Carlo provoked into threatening messages, argued defence

One of the charges was downgraded on Monday from using a carriage service to threaten to kill to threaten to cause serious harm.

Sorry, this video has expired A voice message from Di Carlo to a former employee

Police prosecutor Jeanette Mitchell argued for imprisonment and for Di Carlo to undertake to the court that he would not contact the complainants.

"Regardless of the background the relationships between the defendant and the victims, these messages are more than an annoyance," she said.

"They are menacing, threatening and would be detrimental interference for the victims to proceed with a normal, peaceful life."

However, the defence lawyer Michael Gatenby argued that Di Carlo was provoked by the souring of business relations between himself and the complainants.

Mr Gatenby argued the defendant's business had suffered after the complainants started another business and "took 60 clients from Di Carlo" and after the ABC story aired.

"It is in light of those representations that my client with his back against the wall comes out and says what, in his own words, is inappropriate," he said.

"What is very important to note, there is never any follow-through in any of this."

The defence argued that Di Carlo started undergoing counselling three times a week in November and had accepted that he did the wrong thing.

"When charged by police he used it as an opportunity to rein in his poor demeanour and has immediately taken action to resolve it," Mr Gatenby said.

The maximum jail sentence for each charge is seven years imprisonment.