Another day, another lawsuit. Samsung is suing the Australian patent commissioner in the latest twist in its intellectual property clash with Apple, reports the “BBC” (http://macte.ch/9V5dS).

The South Korean firm is seeking to invalidate four patents which Apple claimed had been infringed by Samsung’s Galaxy Tab 10.1 tablet, the article adds. Samsung alleges that the patents should never have been granted as they duplicated earlier intellectual property filings. A judge will hold a hearing about the matter on June 25.

Apple and Samsung have filed more than 30 lawsuits against each other across four continents. For example, Apple alleges that Samsung copied the slide-to-unlock technology of its iPhone and iPad devices.