Rep. Cunningham is on the Defense Appropriations Subcommittee of the House Appropriations Committee, so the connection (if any) between his work on that subcommittee and the house sale is the likely subject of the investigation, i.e. whether the transaction, which appears to be at an above-market price, was a bribe or unlawful gratuity under 18 U.S.C. Sec. 201.