The 66-year-old businessman, who wrote a book called How to Not Pay Your Debts, says he is "passionate about helping people draw a line in the sand in times of financial distress".

So how did Mr Constable respond when owed money by a former staff member?

In the case of a recent $9000 debt, Mr Constable employed Stephen Gillingham, a former cruiserweight boxer and Bandidos outlaw motorcycle gang enforcer.

Mr Gillingham recently appointed two heavily-tattooed associates to visit the South Melbourne premises of the former employee of Mr Constable.

The two men left a letter of demand and made it clear they knew where he lived.

The man previously employed by Mr Constable declined to make any comment to Fairfax Media, but is understood to have reported the incident to South Melbourne police on August 25.

Mr Gillingham was also involved in debt negotiations with a web developer who worked on a website for Mr Constable's former company, Carlton Ross and Associates. 

Stephen Gillingham is a former cruiserweight boxer and Bandidos outlaw motorcycle gang enforcer.

After not being paid about $5000 for his services, the man is understood to have made disparaging remarks about Mr Constable on a Facebook page. Mr Constable recently settled the debt.

The web designer also declined to comment on the visit from the Bandidos member, and would only say that his lawyer had instructed him not to say anything.

Mr Gillingham, who was arrested at gunpoint in 2013 with Bandidos associate Toby Mitchell in South Melbourne, is the owner and director of debt collection business, Parlay Consulting.

Mr Gillingham's business, which also offers private security and conflict resolution services, is based in the same Doncaster East premises as Mr Constable's former company Carlton Ross and Associates.

On Thursday, Mr Constable defended his decision to employ a bikie to chase debts.

"He [Mr Gillingham] is a collector and from my understanding, he has acted ethically and within the law," he said.

Despite his claims to being an insolvency expert, Mr Constable, who also uses the alias Douglas Duckett, has a long history of failing to pay debts, or taking months to do so.

The 66-year-old has already been declared bankrupt on three occasions since 1988, leaving a string of angry creditors in his wake.

He was convicted of obtaining financial advantage by deception in 1997 and regularly changes business premises.

At least one landlord is said to be owed six months' rent.

In 2013, Mr Constable was denied a liquor licence for a Geelong cafe by the Victorian Commission for Gambling and Liquor Regulation due to "convictions for dishonesty and traffic offences, outstanding warrants and failure to disclose full particulars of his prior convictions".