The $10 million gets London-based Curzon 15% of Tiris' planned production, with Aura able to participate in further offtake finance agreements.
Curzon has the right to provide another $10 million.
Tiris has life-of-mine capex of $90 million and planned annual production of 1 million pounds per annum.
It is currently anticipated to start production in calendar 2023.
All-in sustaining costs are put at $29.80 per pound of production.
Shares in Aura closed 19% higher in Australia at A24c in late trade capitalising the company at $95.8 million.