I think a Royal Commission is different from ordinary summons to appear at court.
ROYAL COMMISSIONS ACT 1902 - SECT 3
1) A person served, as prescribed, with a summons to appear as a witness at a hearing before a Commission shall not:
(a) fail to attend as required by the summons; or
(b) fail to attend from day to day unless excused, or released from further attendance, by a member of the Commission.
Penalty: $1,000 or imprisonment for 6 months.
(1A) Subsection (1) is an offence of strict liability.
Note: For strict liability, see section 6.1 of the Criminal Code .
(1B) Subsection (1) does not apply if the person has a reasonable excuse.
(2) A person appearing as a witness at a hearing before a Commission shall not fail to produce a document or other thing that the person was required to produce by a summons under this Act served on him or her as prescribed or that the person was required to produce by the member of the Commission presiding at the hearing.
Penalty: $1,000 or imprisonment for 6 months.