AppleInsider is reporting that Apple is suing Psystar, makers of computers which have hacked versions of Mac OS X installed.

Apple filed a formal complaint in the U.S. District Court for the Northern District of California on July 3rd. Although exact details are not known, AppleInsider believes that Apple has filed the complaint on grounds of copyright infringement.

In April, Psystar began selling a computer priced at $400 named “Open Computer” which was described as “a low-cost high-performance computing platform” which ran a hacked version of Mac OS X.

The company continued to provoke Apple by last month releasing a server version of its computer running a hacked version of Mac OS X server.