Responding to calls for purpose built national quarantine, The Prime Minster, Scott Morrison, claimed that the hotel quarantine system established in Australia was 99.9 per cent effective. 

Experts contacted by Fact Check took issue with his measure of the "success" of hotel quarantine. However, there were differing opinions on which numbers should be used to measure success. Some experts were of the opinion that the full impact on the community of the breaches should be considered when assessing success. Others suggested more complex calculations which factor in hotel quarantine leaks that have not been discovered by testing or contact tracing.

Furthermore, more complex modelling in available academic research for coronaviruses in other countries suggests a much more robust method of calculating the success of hotel quarantine is possible.

Though experts were not able to point to any such research in the context of Australian hotel quarantine, it is clear that the simple calculation that Mr Morrison has performed is not enough to sustain the claim of such a high rate of success.

One expert used the analogy of an airline to illustrate the point: "If an airline had seven crashes in six months and they defended themselves by saying, 'well, we take more passengers than the other airlines,' would you still fly on that airline? For me, risk is binary when it's a critical system with dire consequences."

The verdict: Mr Morrison's claim is spin.