It's more likely that you would obtain a useful advice if you contact an Australian tax advisor about such tax. If someone has "some experience" with a foreign tax but is not qualified under such jurisdiction, it could be dangerous to rely on such advice (maybe not up-to-date). It's also unlikely that there are many qualified Australian tax advisors in Switzerland who follow the developments under Australian law.

Have you thought of contacting the Australian Mission to the United Nations in Geneva?   They might know of a locally based tax adviser who knows the Australian situation.

Greetings, R.

It's correct that the real estate owned abroad has to be announced in the Swiss tax return (if you file one), but the value of the real estate and the related revenues are not subject to tax in Switzerland (these items are only taken into consideration for the tax rate).

Otherwise, Switzerland and Australia have signed a treaty for the avoidance of double taxation, like most developed countries (member of the OECD).