Bobby Maxwell, a former Minerals Management Service auditor who spent 22 years with the Interior Department unit, tells CNN that he witnessed "inspections" on off shore oil rigs that were barely worth the name.
"They would look at some papers, have lunch, shake hands with their friends and say goodbye," Maxwell told CNN's Abbie Boudreau in an interview scheduled to air Wednesday on AC360.
Maxwell told CNN the agency had a "culture of corruption" and the inspections he saw were like a country fair - all play and no real work.
The agency - which oversees U.S. offshore drilling, including the Gulf of Mexico - has come under fire for mismanagement, questionable conduct and cozy relationships with industry officials.
Interior Department Secretary Ken Salazar, during an appearance before the House Committee on Natural Resources, said he was trying to change the agency's culture and its structure, which some critics say leads to mismanagement.
"My belief is that most of the employees of the MMS are good public servants," Salazar said. He, however, acknowledged some of the past conduct was "scandalous" and "reprehensible."
Maxwell is still litigating a $60 million whistleblower suit he filed against the agency.