Hancock Prospecting billionaire Gina Rinehart has increased her stake in Vulcan Energy Resources to 7.5 per cent after stumping up more than $20 million to help the lithium aspirant secure funding needed to get its flagship project in Germany off the ground.

CIMIC, the country’s largest privately owned builder, will emerge with about 6 per cent of the stock after committing €25 million ($40.85 million) via a private placement.