How would you bring about world peace? What is the most important issue facing the world today? What's your favourite colour?

That's generally the gist of questions tossed at nervous beauty pageant contestants as they try to impress a panel of judges.

No such luck for Miss Universe Australia, Monika Radulovic. Having fought her way into the final five of the gala in Las Vegas, the Sydney beauty was asked if legalising marijuana was a good idea.

Ms Radulovic laughed before thanking comedian Steve Harvey for the rather curly question.

And her reply started out steady enough, until she made the startling claim that marijuana was "really amazing in treating cancer".

It's unclear exactly what the judges made of her answer, but Ms Radulovic failed to progress to the final three.

The drama didn't end there, with host Harvey producing a monumental fail, when he incorrectly announced the winner as Miss Colombia, instead of Miss Philippines.