(Updated with new information) Sen. Amy Klobuchar, burnishing her consumer protection credentials, fired off a letter Tuesday to National Highway Traffic Safety Administration (NHTSA) head David Strickland, calling for a close look at the cooperation between Toyota Corporation and the regulatory agency that enforces safety standards for auto makers. "Since coming to the Senate, I have been troubled by the close relationship between some of our nation's safety agencies and the industries they regulate," Klobuchar wrote in a letter that was released to the press. "Too many times, this relationship has led to a revolving door between government regulators and the industries they oversee. That many NHTSA employees ultimately work for the car manufacturers they once investigated reveals cause for concern." An NHTSA spokeswoman declined a request for comment Tuesday. Klobuchar's office did not respond to a request for names. But recent press reports, citing court documents, have pointed to Christopher Tinto, Toyota's vice president of regulatory affairs, and Christopher Santucci, who works for Tinto. Both men joined Toyota directly from the NHTSA, and reportedly helped end probes by the regulatory agency. Klobuchar's letter comes as the NHTSA announced that it is seeking documents from Toyota to determine if the automaker conducted three of its recent recalls in a timely manner. Federal law requires all auto manufacturers to notify NHTSA within five days of determining that a safety defect exists and promptly conduct a recall. The Minnesota Democrat is a member of the Senate Commerce Committee, which oversees the NHTSA and other transportation agencies. The Committee will hold a hearing on March 2 to review reports of uncontrolled acceleration in Toyota vehicles. Since 2000, there have been 34 alleged fatalities related to unintended acceleration in Toyota products. Since the beginning of the year, Toyota has recalled 7.7 million cars and trucks in the U.S. due to safety issues. In her letter, Klobuchar called attention to the relationship between NHTSA and Toyota, and the way NHTSA responded to consumer complaints in recent years about unintended acceleration in Toyota cars. Her letter cites the case of Jeff Pepski, a Minnesotan who safely guided his Lexus to a stop after experiencing a "dramatic, unintended acceleration." Pepski told Klobuchar that he reported his experience to NHTSA in February 2009, but that NHTSA accepted Toyota's explanation, which hypothesized that the problem was caused by misplaced floor mats – not an engineering defect. Klobuchar said she intends to look closely at the decision-making process that she said may pit the safety of Americans' against industry's concerns. The letter, though scathing, gives Strickland some wiggle room: "I know you have only been in your job for the past few months," Klobuchar concludes. "I hope we can work together to change this culture and this problem."