The judge hearing the criminal case against Pennsylvania Attorney General Kathleen Kane on Tuesday urged her to make public any argument that she has been selectively targeted for prosecution.

Ms. Kane has asked for permission to file court papers under seal in Montgomery County, arguing that she is a victim of "vindictive" and selective prosecution.

Suggesting she is caught between two courts, Ms. Kane has said a Philadelphia judge has suggested that she would violate a court order by bringing such an argument publicly.

But Montgomery County Court Judge Wendy Demchick-Alloy instructed Ms. Kane's lawyers during a hearing Tuesday to get back in touch with that Philadelphia judge, Diana Anhalt, to seek approval to file her argument in open court.

During the hearing, Judge Demchick-Alloy heard arguments, but did not rule, on other appeals by Ms. Kane's lawyers. Among other matters, they have asked that a new judge from outside Montgomery County be appointed to hear the case, saying three other judges on the 22-person bench look unfavorably on Ms. Kane.

The exact thrust of Ms. Kane's argument that she faces selective prosecution is unclear.

Ms. Kane has said she might face a contempt order from Judge Anhalt should the attorney general make her argument in a public filing.

This suggests Ms. Kane is worried that she might violate a protective order that Judge Anhalt issued as the judge presiding over a grand jury investigation of elected officials from Philadelphia who were caught up in an undercover corruption case.

The protective order bans retaliation against witnesses in that investigation. The grand jury has been reinvestigating officials Ms. Kane elected not to charge in the undercover sting case.

Ms. Kane, 49, a Democrat, is accused of leaking confidential information in the spring of 2014 to a reporter for the Philadelphia Daily News about an old investigation headed by former state prosecutor Frank Fina. Prosecutors say Ms. Kane later lied about her role in the leak when questioned about it under oath.

Ms. Kane faces charges of perjury, conspiracy, and and other crimes. She has pleaded not guilty.

Mr. Fina launched the sting investigation. His role in that case suggests that Ms. Kane may want to refer to him in her selective prosecution filing but is concerned that doing so could violate Judge Anhalt's protective order. In filings before the state Supreme Court, Ms. Kane has blamed Mr. Fina for the criminal case against her.

She has also contended that someone from the Montgomery County District Attorney's Office likely leaked to a newspaper the contents of a tape that could be damaging to her.

Ms. Kane's onetime political consultant was captured on the tape discussing her role in asking him to leak confidential documents. Ms. Kane has said the district attorney's office was the only one with a motive to leak information about the recording.

Montgomery County District Attorney Kevin Steele countered Tuesday that perhaps someone in Ms. Kane's camp had leaked the tape, to take "the sting" out of it.

On Tuesday, Judge Demchic-Alloy set a hearing for April 20 to explore how the contents of the tape became public in a story in the Allentown Morning Call newspaper.

First Published: March 23, 2016, 4:00 a.m.