A flashy Australian finance company that sponsored English football team Sheffield United is under intense scrutiny by liquidators over hundreds of millions of dollars in funds investors claim they are owed. Key points: Foreign exchange broker Union Standard International Group collapsed in Australia two years ago Foreign exchange broker Union Standard International Group collapsed in Australia two years ago 7.30 has discovered details of a shell company in the tax haven of Samoa that owns the Australian business 7.30 has discovered details of a shell company in the tax haven of Samoa that owns the Australian business Investors are still…