Renegade Exploration (ASX:RNX) is conducting investigations in California to determine the validity of its mining claims in the Mountain Pass gold and rare earth area, as well as when the competing mining claims over the same area were staked by another party, according to a Monday Australian bourse filing.

It returned to the site to conduct mining claim stake checks and to take photographs for comparison to those taken by the firm's contractor when it first located its mining claims.

The firm said it could begin court proceedings if there is a dispute between the priority of competing claims that cannot be satisfactorily resolved between the relevant parties, among other options.