Woomera Prohibited Area in northern region of South Australia had to be explored for Commonwealth Hill tenements.

Two companies, Western Plains Resources and Apollo Resources, were in joint-exploration venture of this land which is about the size of England and weapons are tested here.

But Western Plains withdrew from this project. The company foresaw the problem of security of tenure issues.

"Until it's released, we do have some concerns about spending high-risk exploration dollars in those parts of the WPA, which are known to be more widely affected by defense activities than other parts", Bob Duffin from Western Plains Resources said.

Earlier also, this situation has been created when the Defense Department gave a doubt on the Hawks Nest joint venture with a Chinese state-owned company because of security concerns.