Montgomery County District Attorney Risa Vetri Ferman says her office will investigate why state Attorney General Kathleen G. Kane fired a top lawyer who had testified against her before a grand jury investigating whether Kane leaked confidential documents.

In a statement Tuesday, Ferman said she would fold that inquiry into her office's ongoing review of whether Kane leaked information to the Philadelphia Daily News last year in a bid to embarrass her critics.

"These inquiries will be conducted using standards and procedures that reflect an ethical prosecutor's responsibilities as a minister of justice," Ferman said.

This month, Kane fired James Barker as part of what she called a restructuring of her office's criminal division.

His ouster came three weeks after The Inquirer reported that Barker had testified against Kane in the leak inquiry, which concluded last year with a grand jury recommendation that she face criminal charges including perjury, contempt, and obstruction of justice.

The judge who oversaw the leak investigation had issued a protective order that prohibited anyone in the Attorney General's Office from retaliating against witnesses who appeared before the grand jury.

This week, a judge made the grand jury's presentment public. The panel concluded that Kane had lied about how and why she released confidential information about a long-closed 2009 investigation of Philadelphia civil rights leader J. Whyatt Mondesire. Mondesire has denied wrongdoing and was not charged with a crime.

Kane has acknowledged authorizing the release of some of the information but has maintained that it was not secret. She has also argued that she was not bound by grand jury secrecy rules because she was not the attorney general in 2009 and had not taken a secrecy oath.

Barker, in his testimony before the grand jury that investigated the leak, contradicted Kane. According to the grand jury, he testified that the documents released to the Daily News were grand jury materials and that such documents are to be kept secret.

The leak case was turned over to Ferman this year, and she has said she is reviewing it. On Monday, a three-judge panel referred the Barker matter to Ferman and asked her to investigate whether his dismissal violated the protective order.