WASHINGTON (Reuters) - A leading Democratic lawmaker on Tuesday accused Secretary of State Condoleezza Rice of interfering in congressional inquiries into corruption in Iraq’s government and the activities of U.S. security firm Blackwater.

Secretary of State Condoleezza Rice talks during an interview with Reuters in New York, September 24, 2007. REUTERS/Brendan McDermid

Democratic Rep. Henry Waxman said State Department officials had told the Oversight and Government Reform Committee he chairs they could not provide details of corruption in Iraq’s government unless the information was treated as a “state secret” and not revealed to the public.

“You are wrong to interfere with the committee’s inquiry,” Waxman said in a letter to Rice. “The State Department’s position on this matter is ludicrous,” added Waxman, a vocal opponent of the Bush administration’s Iraq policies.

The State Department had no immediate comment on the letter or Waxman’s allegations of interference but it has in the past dismissed the California lawmaker’s comments as partisan.

Waxman said security contractor Blackwater, which was involved in an incident in which Iraqi civilians were killed last week, said they could not hand over documents relevant to an investigation without State Department approval.

“Congress has a constitutional prerogative to examine the impacts that corruption within the Iraqi ministries and the activities of Blackwater may have on the prospects for political reconciliation in Iraq,” Waxman wrote to Rice.

Blackwater provides security for the U.S. Embassy in Baghdad and has a contract with the State Department.

The company was involved in a September 16 shooting in which 11 people were killed while Blackwater was escorting a convoy through Baghdad. The State Department is investigating the incident along with the Iraqis.

Waxman, who has called a hearing on Blackwater for October 2, released a letter his staff received from the security contractor’s attorneys dated September 24.

“It (the State Department) directs Blackwater USA not to disclose any information concerning the contract without DOS (Department of State) preauthorization in writing.”

Blackwater also urged the committee not to ask questions at the hearing that could reveal sensitive information “that could be utilized by our country’s implacable enemies in Iraq.”

Such information included the size of their security staff in Baghdad, weaponry and the operation of convoys.

Waxman also released a letter signed by State Department contracting officer Kiazan Moneypenny to Blackwater.

“I hereby direct Blackwater to make no disclosure of documents or information ... unless such disclosure has been authorized in writing by the contracting officer,” wrote Moneypenny.

Waxman also complained Rice was refusing to testify at any hearings his committee planned to look at political reconciliation in Iraq, corruption or the Blackwater incident.