Updated

The World Bank has appointed a high-profile Washington law firm to investigate the disclosure of confidential documents and e-mails leaked to FOX News, which it said violated bank rules.

In a message to staff dated April 9, the bank's legal department said it had appointed Williams & Connolly, a well-connected Washington law firm, to probe unauthorized disclosures that provided the basis for stories carried by FOX News' Web site.

A Jan. 30 FOX story posted confidential minutes of a board meeting, which outlined a rift between World Bank President Paul Wolfowitz and the bank's board of member countries.

Click here to read the FOXNews.com story that sparked the investigation.

• RAW DATA: Internal World Bank E-Mail (pdf) | Key to Acronyms and Staffers

The FOX report included information it called "unflattering descriptions about some directors" and said the board dispute "illustrates the explosive level of animosity currently focused on Wolfowitz and his management team by the World Bank board."

The story, along with another piece published on March 27, caused an uproar among members of the bank's board, made up of representatives and advisors of the 185 member countries.

"These disclosures of confidential internal communications violated Bank policy," the World Bank said in a message to its staff, obtained by Reuters. "The Bank is taking these violations very seriously."

The probe is the second controversy to hit the World Bank in just over a week.

On Monday, Wolfowitz pledged to cooperate in a review by the bank's board of the promotion and pay increase of a female staffer, Shaha Riza, with whom he is having a personal relationship. That probe is focused on whether Wolfowitz gave preferential treatment to Riza, violating staff rules.

Wolfowitz joined the bank in mid-2005 after serving as deputy defense secretary at the Pentagon, where he was one of the chief architects of the Bush administration's war strategy in Iraq.

In the latest investigation concerning the documents leaked to FOX, Wolfowitz and the board called for all staff to cooperate. "The board and the president ask that everyone give these representatives their full cooperation," the note said.