For the purposes of this Part, a person has a child support liability if:
(a) the person has a registrable maintenance liability of a kind mentioned in section 17 or 17A, subsection 18A(1), paragraph 18A(3)(a) or subsection 18A(4) (insofar as subsection 18A(4) relates to subsection 18A(1) or paragraph 18A(3)(a)); and
(b) an amount payable under the registrable maintenance liability is a child support debt; and
(c) the day on which the debt became due and payable under section 66 has passed, and the debt remains unpaid in whole or in part.