In this Act, unless the contrary intention appears:
"Commonwealth employee " means:
(a) an APS employee; or
(b) an employee of a body (whether incorporated or not) established for a public purpose by, or under, a law of the Commonwealth.
"officer " means:
(a) a Commonwealth employee; or
(b) a person who performs services on behalf of the Department under a contract made between the person and the Commonwealth; or
(c) an employee of a person referred to in paragraph (b).
"Secretary " means the Secretary of the Department.