A federal judge on Friday froze the assets of Boston Grand Prix president John Casey as part of an $11 million bankruptcy case stemming from the collapse of an Indycar race that had been planned for the Seaport District last Labor Day weekend, the Boston Globe reported on Saturday. The ruling by Bankruptcy Judge Joan N. Feeney came after Casey was accused last week in court filings of using the Boston Grand Prix as “his personal piggy [bank].” “John Casey spent hundreds of thousands of dollars of Boston Grand Prix’s money for personal expenses without regard for the interests of creditors,” said attorney Kate Cruickshank of the firm Murphy & King, who is representing creditors in the case. “It’s the job of the bankruptcy trustee to recover assets belonging to Boston Grand Prix for all creditors.”