WASHINGTON (Reuters) - Defense Secretary Donald Rumsfeld on Tuesday sidestepped a question about his role in approving a failed $23.5 billion deal to acquire Boeing Co tankers, saying he would have to refresh his memory.

At least one criminal probe is still under way related to the Air Force plan to lease and then buy up to 100 Boeing KC-767A tankers to refuel airplanes in mid-flight. Violations of federal acquisition rules have also been disclosed in connection with the deal.

At a Pentagon news briefing, Rumsfeld declined comment on what would be done to punish wrongdoers associated with the deal. He said a report made public last week by Pentagon Inspector General Joseph Schmitz would be "studied and evaluated and judgments would be made about it."

Asked when he expected any decisions to be made, Rumsfeld answered, "I don't do time frames."

Asked about his own role in the deal, Rumsfeld declined comment, saying, "I'd have to go back and read this (report) and then talk to the people involved to refresh myself."

Schmitz last week told Congress that senior Pentagon and Air Force officials bypassed normal procedures in an "inappropriate" rush to push the deal, and he said at least one related criminal probe was still under way.

Rumsfeld was not one of the "primary decision makers" named in the report. They were former top Pentagon weapons buyer Edward Aldridge; former Air Force Secretary James Roche; his weapons buyer, Marvin Sambur; and Darleen Druyun, the Air Force's former No. 2 weapons purchaser, now imprisoned.

Aldridge, now a board member for Lockheed Martin Corp., had announced the proposed deal in May 2003, days before retiring, saying it had been approved by Rumsfeld.

Officials in the Inspector General's office have said Rumsfeld and then-Deputy Defense Secretary Paul Wolfowitz had told them they had left the decision up to Aldridge, the Pentagon weapons buyer, and then merely supported it.

But in a letter included in the report, former Air Force Secretary Roche said Rumsfeld called him in July 2003 and said "he did not want me to budge on the tanker lease proposal," despite emerging criticism.

Roche said it was a myth to attribute the proposed deal solely to the Air Force, saying: "It was not. It was a proposal of the Department of Defense and the administration."

Three of four congressional committees initially backed the lease deal, but Congress ultimately killed it last year after Druyun admitted inflating the price of the tanker deal and steering billions of dollars' worth of other contracts to Boeing.

Druyun is serving a nine-month prison sentence after pleading guilty to violating conflict of interest rules by negotiating a $250,000-a-year job at Boeing while still overseeing the company's Air Force contracts.