An Australian traveller says his “mind is blown” over a persistent curling issue with the “world’s most expensive” passport.

The citizen slammed the “horrendous” quality of the R Series travel document, which has drawn criticism for automatically bending in humid conditions.

“My mind is blown. Our passport is the most expensive in the world and the quality of them is horrendous,” the frustrated traveller said in a post on social media.

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Their post included a picture demonstrating how the document had folded back at the edges without interference.

“I got this passport a month or two ago for my current trip and every time it’s not in a sleeve for more than an hour, this happens,” they said.

“No, it’s never gotten wet, or (had) any weather damage. This is just how it is. I know Malaysia’s humidity is bad but no way it’s this bad.”

The traveller, who asked to remain anonymous, told 7NEWS.com.au his photo of the $398 document curling up “like a plant” was taken after it had been sitting in a temperature-controlled room set to 18C for eight hours.

“I’d had no issues with the old one. The old passport looks newer than this one, which is the most ridiculous part of it,” they said.

The uni student said the passport “fixes itself less and less and less” after each time it folds, and was unacceptable considering the cost and how authorities had talked up its features.

He hopes something can be done to limit the problem now and said a fix has to be implemented with future passports.

He said authorities in Malaysia had given it a “second look and a pull” when he arrived and feared travellers who use it as their primary form of ID overseas could be left vulnerable if security believed they are fake documents.

‘No idea’

The post triggered a wave of responses, with many sharing how they had experienced the same thing with the $398 travel document.

“Mine has lived under a heavy book ever since I got it because of this,” one person said.

“No idea how it was never caught. It didn’t even take long to start happening.”

Another claimed their passport was curling “inside the envelope it arrived in”.

A third said it was only a “matter of time” before an Australian traveller is “stranded” because their passport is refused.

“Hope we don’t have to pay for replacements,” they said.

New Zealand and Canadian passports have also been found to be sensitive to humidity and heat.

The Australian Passport Office addressed the problem on its website, saying the curling does not invalidate the document and is nothing to be concerned about.

“You may notice a slight curling on the cover of your R Series passport. This occasionally occurs due to changes in humidity,” the office said.

“It’s not a manufacturing defect and doesn’t affect the validity of your passport.

“Keeping your passport tightly secured will help prevent this curling.

“For example, you can use an envelope or passport holder to store and protect your passport between use.”

Quality concerns

Beyond the curling, others wondered whether their passports would last the 10 years they are valid for.

One person claimed theirs “already has several loose pages”.

It was a common concern, with another claiming the pages of their son’s travel document seem to be “holding on by the merest thread” even though he has not used it yet.

The Department of Foreign Affairs and Trade (DFAT) talked up the “next-generation passport” last year, saying the R Series was “packed with advanced security features designed to keep Australians’ identities safe”.

“The photo page is made of tough, high-security, layered plastic, known as polycarbonate,” the department said.

“Polycarbonate is laser-engraved, not printed with ink. Photos on the photo page appear in black and white rather than in colour.

“But the R Series is not only jam-packed with high-tech innovations, it’s also visually stunning.

“The visa pages proudly showcase 17 iconic landscapes from around our beautiful country. Under ultraviolet light, the sky in each image becomes a unique nightscape, and a local species of native fauna appears.”

The advice for keeping the valuable travel document in top shape is to know where it is at all times, keep it dry, not alter it and never allow someone else to use it.

“Be careful to not bend the cover back or you could damage the stitching that holds the passport together,” the department said.

“Ink from boarding passes can transfer to your passport photo page and obscure the details. It’s a good idea to keep your boarding pass away from your photo page.

“Keep a photo or photocopy of your passport’s photo page, or at least a record of its number and expiry date. This can be useful for your own reference and in certain travel situations.”