Gibbons' lawyer Abbe Lowell said the lead prosecutor has informed him that no charges will be filed against the governor and the case is now closed, The New York Times reported Monday.
The 18-month investigation began after a former staff member of the technology company run by a friend of the governor made accusations of influence-peddling when Gibbons served in Congress.
The former staff member accused Gibbons of receiving gifts in exchange for helping eTreppid Technologies win military contracts. The company makes software used by intelligence agencies and military units.
The federal investigation eventually expanded to include consulting payments to the governor's wife from another Nevada military contractor, The Washington Post repored.