It is a "mystifying" act of fiction by one of US President Donald Trump's closest advisors that spanned the course of nearly two decades.

Peter Navarro is a top White House trade advisor, a loyal member of Mr Trump's inner circle, a free trade critic and an outspoken China hawk.

In at least six of his books, Mr Navarro quoted someone who he called a stock trader "in a league of his own" - fellow Harvard alumni Ron Vara, who has offered such hardline musings on China as: "only the Chinese can turn a leather sofa into an acid bath, a baby crib into a lethal weapon and a cellphone battery into heart-piercing shrapnel".

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According to 2006 non-fiction book, The Coming China War, Mr Vara even suggested, "you've got to be nuts to eat Chinese food".

The problem is Ron Vara does not exist.

He is a made-up alter ego, who first featured in Mr Navarro's 2001 book If It's Raining in Brazil, Buy Starbucks.

In fact, the name Ron Vara is almost an anagram of Mr Navarro's name.

An Australian discovery

The discovery was made accidentally by Australian National University scholar Tessa Morris-Suzuki during her research to write a blog piece on anti-China rhetoric.

"It was really, entirely by accident," the emeritus professor told SBS News.

It was really, entirely by accident Tessa Morris-Suzuki

"I was looking at some of Peter Navarro's writings and came across a couple of quotations that I thought were quite concerning from this person called Ron Vara, which made me curious about who Ron Vara was," she said.

"So I started looking for him, assuming I would find him quite easily, on the internet, and he wasn't there."

That discovery – or lack thereof – left Professor Morris-Suzuki stunned.

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"I was mystified. Obviously I thought I wasn't looking hard enough. But then when I started doing what fact checking I could, I realised that there was something strange going on here."

The Chronicle of Higher Education published some of Professor Morris-Suzuki's findings and the story was ultimately picked up by The New York Times and CNN.

The fictional character was unknown even to Mr Navarro's publishers.

Pearson Publishing said it is now adding an addendum to Mr Navarro's books, warning of Ron Vara.

SBS News

Mr Navarro, though, is unapologetic.

"[Ron Vara is a] whimsical device and pen name ... for opinion and purely entertainment value, not as a source of fact," he told The Chronicle.

"[It's] refreshing that somebody finally figured out an inside joke that has been hiding in plain sight for years."

'Worrying wake up call'

But Professor Morris-Suzuki said this is no laughing matter.

"I find it really worrying because obviously the US-China relationship is just one of the most important issues in the world today. And obviously there's plenty to criticise about China," she said.

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"It's not the fact that Navarro is criticising China that I'm worried about. But the criticism needs to be really well-founded, it needs to be based on really careful knowledge, and not on very extreme claims, and not on stirring up a kind of fear and panic about China - and I think that's what some of his writings do."

She also said the Australian government should be concerned.

"I find it very worrying ... for Australia as we think about how our government should be dealing with China. It should be sort of a wake up call that we need to be careful about where the Trump White House is going in its relationship with China,” she said.

But Mr Navarro appeared not to be taking his own advice.

In September this year, he told CNBC: "Any news that you hear about China that doesn't quote real sources ... just don't believe it. Treat it as entertainment, not information".

Neither the White House, or Mr Trump, have commented on the developments.