Federal investigators are probing state Senate Majority Leader Dean Skelos’ sources of income and his connection to the real-estate industry, NBC 4 New York reported Thursday, citing people familiar with the investigation. The highest-ranking Republican in state government has come under investigation just one week after Democratic Assembly Speaker Sheldon Silver was charged for allegedly taking $4 million in bribes. Silver has denied the charges. A spokesman for Skelos did not return phone calls for comment Thursday. U.S. Attorney Preet Bharara has cracked down on corruption in Albany, specifically looking at how some part-time legislators are making money outside of government. A spokesman for Bharara declined to comment as well as FBI spokesmen in New York and Washington, D.C.