Self-proclaimed extreme body modifier Brendan Leigh Russell, 40, faces years in prison if convicted of intentionally causing grievous bodily harm to a woman in his studio in Erina Fair shopping centre in November 2016.

His District Court trial has heard allegations the mother signed no consent form and was provided little information about the procedure.

Even if she did provide consent, Judge Helen Syme "could be extremely confident there is no defence in a body modification case to simply claiming the person subject to the procedure consented to it," crown prosecutor Chris Taylor said on Tuesday.

The mother said Russell told her it would be a "pretty much easy procedure".

But she was left in "extreme pain" and required surgical intervention to overcome substantial scarring and infection.

Mr Taylor dismissed comparisons to criminal cases against suspended medical practitioners.

"There's a world of difference because, number one, he is not a registered medical practitioner," he said.

The body modifier has pleaded not guilty to the grievous bodily harm charge and two others related to women he saw between 2015 and 2017.

He accepts he did partially excise a woman's labia in January 2015 but denies breaking a law forbidding such procedure in non-medical circumstances.

Mr Taylor said there was no defence available and any suggestion the law only applied to child victims was wrong.

IN THE NEWS:

It was "blatantly obvious" parliament intended to outlaw all non-medical genital mutilation, not just ritualistic ones on children, he said.

The Crown also alleges Russell played a causative part in the events that led to the sepsis-related death of a customer in April 2017.

The customer, who along with the other women cannot be named, died two weeks after a plastic snowflake was implanted in her hand.

The procedure was "high-risk" and after infection, Russell "deterred" the woman from seeking the medical treatment that was required, the Crown alleges.

"(He) assured the deceased her hand was not infected when it was and ... simply encouraged the deceased to take migraine pain medication," Mr Taylor said.

Evidence of medical experts about the cause of the woman's death meant the judge could find beyond reasonable doubt that Russell breached his duty of care and was criminally negligent, the Crown said.

One expert called by the defence said it's only a 50-50 chance the woman died of sepsis.

The trial has been told Russell claimed to customers that he had a "full extensive surgical background of training".

Procedures offered included tongue splitting, ear lobe reconstruction, ear cartilage removal, belly button removal, genital implants and branding.

Russell's lawyer, Michal Mantaj, will deliver his closing address after Mr Taylor.

Our journalists work hard to provide local, up-to-date news to the community. This is how you can continue to access our trusted content:

The trial, before Judge Helen Syme without a jury, continues.