By David Thomas

Aug 26 (Reuters) - Ex-U.S. bankruptcy judge David Jones can be questioned about his once-secret relationship with an attorney whose former law firm appeared in cases before him, including whether he was biased toward the law firm, a Houston bankruptcy judge ruled on Saturday.

Chief Bankruptcy Judge Eduardo Rodriguez said Jones can be questioned by U.S. law firm Jackson Walker and the U.S. Trustee, the Justice Department's bankruptcy watchdog, over his relationship with Elizabeth Freeman.

Judicial policy prohibits judges from testifying about their official acts without authorization. Rodriguez said Jones and his former case manager, Albert Alonzo, will be questioned under his supervision, as some of the questions could run up against that policy.

Jackson Walker and the U.S. Trustee said they want to ask Jones when his relationship with Freeman began and when they began living together, and whether his relationship resulted in any rulings that were biased toward the law firm, among other things.

Jones, Freeman, Alonzo and their lawyers did not immediately respond to requests for comment, nor did a spokesperson for the U.S. Trustee. A Jackson Walker spokesperson declined to comment.

Jones was once the busiest bankruptcy judge in the U.S. and had recently presided over the bankruptcies of JCPenney, Neiman Marcus, Party City and Chesapeake Energy, among many others. He resigned from the bench last October after admitting to sharing a home with Freeman.

Since then, the U.S. Trustee has been trying to force Jackson Walker to disgorge millions of dollars in legal fees that Jones approved in 35 bankruptcy cases filed by the law firm. Rodriguez is overseeing that litigation.

During a hearing earlier this month, Jones confirmed he was under criminal investigation.

Rodriguez sanctioned Jones earlier this month for offering testimony outside of the court's supervision.

(Reporting by David Thomas)

((D.Thomas@thomsonreuters.com;))