Northern Minerals has asked the Foreign Investment Review Board to probe whether recent share acquisitions are a covert attempt by Chinese interests to gain control of the rare earth play’s strategically important assets in Western Australia.

Northern Minerals revealed its suspicions and the request for a FIRB investigation late on Monday, some seven months after Treasurer Jim Chalmers moved to prevent the Singapore-registered Yuxiao Fund increasing its stake to 19.9 per cent from 9.81 per cent.