Former One Nation senator Rod Culleton outside the High Court in December.Credit:Alex Ellinghausen
Senator Parry advised party leaders and independent senators of the disqualification under section 45 of the constitution,which sees senate seats vacated if a senator is declared bankrupt.
He said the move did not end the question over the Senate's composition.
"The Senate has referred to the Court of Disputed Returns questions about the eligibility of Rod Culleton to have been chosen as a senator,"he said in a statement.
"It will be necessary for the Court of Disputed Returns to deliver its answers to the referred questions before it will become apparent how the vacancy may be filled.