Income taxes (Restated) (Details) - USD ($)	3 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Jun. 30, 2020
Income taxes (Restated) (Details) [Line Items]
Income tax expenses
Operating loss carryforwards			$ 6,456,000
Net operating loss tax benefit	549,000
Tax benefit derived from such NOL	115,000
Future taxable income	675,000
Federal taxable income net operating loss	1,400,000
Net operating loss	1,000
Taxable income	$ 5,964,000
Allowance of DTA	100.00%
Deferred tax assets amount	$ 270,000
UNITED STATES
Income taxes (Restated) (Details) [Line Items]
Future taxable income	7,005,000
PRC [Member]
Income taxes (Restated) (Details) [Line Items]
Operating loss carryforwards			$ 5,961,000
Net operating loss tax benefit	$ 3,000