A federal grand jury in Lexington has indicted former Kentucky Transportation Secretary Bill Nighbert and road contractor Leonard Lawson following an FBI investigation into alleged bid-rigging on highway construction projects.The indictment accuses Nighbert of accepting payments funneled through a utility management company in exchange for helping leak secret cost estimates on certain road projects to Lawson.Also charged in the case is Brian Billings, an aide to Lawson.Attorneys for Lawson and Billings both say their clients violated no laws. Neither Nighbert nor his attorney had any immediate comment.Governor Steve Beshear says the charges are what he called "further evidence of a culture of corruption" in the cabinet in years past."We have very high standards now and now we expect our folks to live up to it. I believe they are and we're pushing forward very aggressively in the transportation cabinet and all over state government to be sure we do," he said.The indictment says the crimes occurred in 2006 and 2007, during the administration of former Governor Ernie Fletcher.