The answer is a big yes! I too was wondering about this recently and couldn't find any clear information the interweb. I rang the Family Assistance Office. I was advised by the fabulous helpful person on the phone that you can claim CCR for up to 12 months whether on paid or unpaid maternity leave.
I was told the same thing provided I was actually going back to work rather than resigning while I was on leave.. ITMS?? And yes I got it while I was on unpaid mat leave