No employe, appointee or official in the Executive Branch of the Commonwealth may represent or act as agent for a private interest, whether for compensation or not, in a transaction in which the State has a direct and substantial interest and which could be reasonably expected to result in a conflict between a private interest of the official or employe and his official State responsibility.
4 Pa. Code § 7.152
This section cited in 4 Pa. Code § 7.159 (relating to enforcement).