Australian billionaire Gina Rinehart and her company Hancock Prospecting have built up a 5.82% stake in Lynas Rare Earths, after investing just over AUD 40 million ($25.6m) in 6.6m new ordinary shares.

According to a Lynas filing late on Tuesday, Rinehart has been purchasing shares in the company since December. The nine transactions to date have given the businesswoman a total of 54.43m shares in Lynas, Kallanish learns.

The Perth-based company is described as the world’s “only” significant producer of separated rare earth materials outside of China. It targets the global manufacturing supply chains in east Asia, Europe and North America.

Lynas processes concentrate from its Mt Weld mine in Western Australia at its facility in Kalgoorlie and the advanced materials plant in Kuantan, Malaysia. The firm is also building a new processing facility in Texas, US to separate pre-processed mixed rare earths.

Earlier this year, Lynas confirmed it had held “confidential discussions” with US-based MP Materials Corp regarding a “potential transaction.” At the time, the speculation was that the companies were studying a merger, which failed to materialise. Such speculation is now re-emerging as Rinehart has recently acquired a 5.3% stake in MP Materials, which is building magnet production capacity in Texas.

The recent rare earth addition to Hancock’s mining portfolio is in line with Rinehart’s ambitions to safeguard Australian resources from China. The businesswoman also seems to ensure Australian resources remain on Australian hands. Last year, Rinehart blocked SQM’s proposed acquisition of Azure Minerals by raising its investment and voting power in the company. She has since agreed on a deal with the Chilean firm, the world’s second-largest lithium producer, to acquire Azure together.

Hancock also has a 5.85% stake in Brazilian Rare Earths, an Australia-listed company, while Rinehart owns a 10% share in Northern Territory’s Arafura Rare Earths. Neither Rinehart nor Hancock have publicly commented on the speculation related to Lynas and MP Materials tie-up.

On Wednesday, Australian Prime Minister Anthony Albanese highlighted the country’s rare earths deposits offer major global advantages. Speaking at a press conference in Gladstone, he said Australia is “really well positioned” in terms of critical minerals, with 31 identified and supported to date.

“If you look at all the products that will power the 21st century, Australia is the lucky country. Australia has massive quantities of copper, vanadium, cobalt, rare earths, of a range of products that will be so important as we go forward,” he says. “If we get this right, we can position ourselves so that our economy not only is able to supply domestically, but we are able to export, particularly the growing economies to our north.”