An Australian journalist who named her son Methamphetamine Rules has been grilled over the blunder on A Current Affair.

Host Allison Langdon conducted an interview with presenter Kirsten Drysdale on Tuesday night, after news.com.au reported how the New South Wales, Australia Registry of Births, Deaths and Marriages let the obscene name slip through its processing system.

Drysdale had been working on a story for the network’s WTFAQ series on the topic of what Australians can legally name their babies. In a bid to figure out the Registrar’s process, she submitted the name ‘Methamphetamine Rules’ for her newborn son believing it would never get approved.

Appearing on the Channel 9 current affairs program to discuss the unusual turn of events, Drysdale was left visibly stunned by Langdon’s stern line of questioning.

“Did the epidural block the brain? Why would you do this to your baby boy?” Langdon began.

“I did this in the name of journalism, Ally,” a lighthearted Drysdale said, before the interview took more of a serious tone.

Langdon continued: “I know that when you fill in a passport form you have to answer if you’ve gone by another name, so baby Meth won’t have to tick ‘yes’ to that?”

“No, he won’t, because that’s if you do a ‘change of name’,” Drysdale argued. “This is a different thing, it’s a ‘correction’, so there’s no endorsements on the bottom of the birth certificate that way.”

Langdon mused the situation was “a bit of a stunt”, before asking, “Did you take it too far?”

Looking to the side of the camera for a brief moment, Drysdale said, “Um, no. I would hope that there are no parents out there who would seriously call their child a name like that.

“But if they are calling their child a questionable name, I think we’ve shown that there needs to be some better checks on it.”

Langdon conceded some people would no doubt find the story “hilarious”, but added, “others, I imagine, are appalled.”

Drysdale again defended her position, assuring there was “no lasting harm done”.

“We checked what the risks were before we did it and we’ve shown that there probably needs to be some tightening up of the processes to make sure when people fill out these forms that they are actually checked properly,” she said.

The NSW Registry told news.com.au it had tightened its system following the mistake.

“The Registry has since strengthened its processes in response to this highly unusual event,” the spokesperson said.

“The vast majority of parents do not choose a name for their newborn baby that is obscene, offensive or contrary to the public interest.”

Drysdale was trying to figure out what default name the Registrar chooses for babies whose first submissions aren’t accepted by the government body.

“Methamphetamine Rules, we thought would surely get rejected, and then when it does, we can find out what name the Registrar chooses,” she told news.com.au Tuesday.

“It was really just a lighthearted, curious attempt to get an answer to this question.”

Thankfully, the Registrar admitted it was a rare oversight, and Drysdale’s son’s real, “normal” name should be approved any day now.

“Baby Meth’s real name … I’m not publicly disclosing it, because I don’t want it to be attached to this,” Drysdale laughed.

“It’s a beautiful name and I can tell you has nothing to do with class A drugs.

“We think it’ll be a very unique 21st birthday present to tell him this story.”

As a general rule, names that are prohibited in most states and territories across Australia are ones that are offensive or contrary to the public interest.

Swear words, sex acts and slurs of any kind are also black-listed, as are official titles such as Doctor, Queen, King and Prime Minister.

While there are clear restrictions, the individual registrars judge names on a “case-by-case” basis.