Share-based payments - Summary of valuation for each tranche of options (Detail)	12 Months Ended
Jun. 30, 2020 AUD ($) yr $ / shares	Jun. 30, 2019 $ / shares
Tranche 4 [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Grant date	Nov. 16, 2015	Nov. 16, 2015
Expiry date	Nov. 16, 2020	Nov. 16, 2020
Share price at Grant Date	$ 0.140
Exercise price	$ 2.200	$ 2.200
Volatility (%)	158.00%
Remaining Option Life \| yr	0.37
Risk free Rate	2.04%
Fair value per option \| $	$ 1.280
Tranche 8 [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Grant date	Sep. 05, 2016	Sep. 05, 2016
Expiry date	Sep. 05, 2021	Sep. 05, 2021
Share price at Grant Date	$ 0.105
Exercise price	$ 1.630	$ 1.630
Volatility (%)	122.00%
Remaining Option Life \| yr	1.16
Risk free Rate	1.60%
Fair value per option \| $	$ 0.840
Tranche 9 [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Grant date	Oct. 12, 2016	Oct. 12, 2016
Expiry date	Oct. 17, 2021	Oct. 17, 2021
Share price at Grant Date	$ 0.098
Exercise price	$ 1.560	$ 1.560
Volatility (%)	122.00%
Remaining Option Life \| yr	1.29
Risk free Rate	1.89%
Fair value per option \| $	$ 0.780
Tranche 10 [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Grant date	Oct. 31, 2016	Oct. 31, 2016
Expiry date	Nov. 01, 2021	Nov. 01, 2021
Share price at Grant Date	$ 0.090
Exercise price	$ 1.380	$ 1.380
Volatility (%)	122.00%
Remaining Option Life \| yr	1.20
Risk free Rate	1.87%
Fair value per option \| $	$ 0.720
Tranche 11 [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Grant date	Nov. 21, 2016	Nov. 21, 2016
Expiry date	Nov. 23, 2021	Nov. 23, 2021
Share price at Grant Date	$ 0.092
Exercise price	$ 1.380	$ 1.380
Volatility (%)	122.00%
Remaining Option Life \| yr	1.20
Risk free Rate	2.10%
Fair value per option \| $	$ 0.730
Tranche 12 [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Grant date	Aug. 07, 2017	Aug. 07, 2017
Expiry date	Aug. 07, 2022	Aug. 07, 2022
Share price at Grant Date	$ 0.430
Exercise price	$ 0.670	$ 0.670
Volatility (%)	74.50%
Remaining Option Life \| yr	2.08
Risk free Rate	1.95%
Fair value per option \| $	$ 0.206
Tranche 13 [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Grant date	Feb. 05, 2018	Feb. 05, 2018
Expiry date	Feb. 05, 2023	Feb. 05, 2023
Share price at Grant Date	$ 0.500
Exercise price	$ 0.780	$ 0.780
Volatility (%)	74.50%
Remaining Option Life \| yr	2.58
Risk free Rate	1.95%
Fair value per option \| $	$ 0.200
Tranche 14 [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Grant date	Jan. 04, 2019	Jan. 04, 2019
Expiry date	Jan. 04, 2024	Jan. 04, 2024
Share price at Grant Date	$ 0.340
Exercise price	$ 0.492	$ 0.492
Volatility (%)	74.50%
Remaining Option Life \| yr	3.50
Risk free Rate	1.95%
Fair value per option \| $	$ 0.140
Tranche 15 [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Grant date	Nov. 13, 2019
Expiry date	Jan. 04, 2024
Share price at Grant Date	$ 0.410
Exercise price	$ 0.492
Volatility (%)	74.50%
Remaining Option Life \| yr	4.20
Risk free Rate	1.95%
Fair value per option \| $	$ 0.180
Tranche 16 [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Grant date	Jan. 13, 2020
Expiry date	Jan. 13, 2025
Share price at Grant Date	$ 0.620
Exercise price	$ 0.881
Volatility (%)	74.50%
Remaining Option Life \| yr	4.50
Risk free Rate	1.95%
Fair value per option \| $	$ 0.340

The date on which share-based payment arrangements are granted. [Refer: Share-based payment arrangements [member]]

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The expected volatility of the share price used to calculate the fair value of the share options granted. Expected volatility is a measure of the amount by which a price is expected to fluctuate during a period. The measure of volatility used in option pricing models is the annualised standard deviation of the continuously compounded rates of return on the share over a period of time.

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The option life of share options granted.

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The implied yield currently available on zero-coupon government issues of the country in whose currency the exercise price for share options granted is expressed, with a remaining term equal to the expected term of the option being valued (based on the option's remaining contractual life and taking into account the effects of expected early exercise). [Refer: Government [member]]

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The exercise price of share options granted.

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The weighted average fair value of share options granted during the period at the measurement date. [Refer: Weighted average [member]]

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The date on which share-based payment arrangement options expire.

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Share price per share.

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