Howard Rollins, also known by his moniker Luna Cobra, has pleaded not guilty after allegedly coaching another man to remove a woman's labia at a Newcastle tattoo parlour five years ago.

In Sydney's Downing Centre District Court on Wednesday, former client John 'Ox' Brady claimed he had once asked Rollins, 42, to perform a procedure on his genitalia.

"Howie actually refused to," he said.

"He said he doesn't like doing genital work. I don't know if that's male genital work or female genital work."

The carpenter, who has tattooed eyeballs and marks on either hand bearing the characters "O" and "X", told the court he hadn't had any contact with Rollins since 2016.

Mr Brady said the American citizen issued him an ultimatum, forcing him to choose between remaining friends with him or the accused perpetrator.

When he did eventually reach out again with a text message, Mr Brady said Rollins "politely told me to F off and never contact him again".

"I wished I could get more (work) from him but he terminated the friendship," he said.

Rollins concedes he visited the studio that day in January 2015, but denies being in the room while the woman had her labia cut off with what she describes as a "branding iron".

The court has heard the woman was later handed her body parts in a jar filled with a preservative liquid.

Mr Brady said he told police, during a two-hour interview, that the victim had admitted Rollins "didn't do it".

But crown prosecutor Georgia Turner noted that claim hadn't appeared in his original sworn statement.

"Not everything I said was put in," he said.

"(The officer) said if I couldn't be exact about details, we'll leave them out."

Frustrated by perceived delays which hindered him from giving evidence earlier this week - which Mr Brady says prevented him from fixing his home's tree-damaged roof - he was phoned by a detective after sending her some "angry" text messages.

Ms Turner suggested he'd claimed Rollins had been "set up" and he wanted to "help" the eyeball tattoo specialist during the course of the conversation.

But the tradesman couldn't recall using those exact words.

"I'm not helping or hindering," Mr Brady said.

"I'm telling the truth."

Unless conducted as medical treatment, female genital modification is illegal under NSW law - even if done so consensually.

The trial before Judge Ian Bourke resumes on Thursday.

Australian Associated Press