Will I get pulled up at Airport?

Hi I am living in nz but flying to aus soon with my family and am scared I might be pulled up at the airport because approx 17 yrs ago I was living in aus with my dropkick now ex, both of us on the dole. He got a credit card in his name but mine was the 2nd guaranteur type thing ... I think it was about $6000 then we left the country I cancelled our dole but overseas we found it was still being paid so he got me to withdraw it I think 3 payments so about $1800. Thrn got lettrrs saying they were investigating our bank account etc. Thats the last i heard and I've never been back. I was young and dumb shit scared and in an abusive relationship I soon escaped him but I've always had this hanging over my head. What do u think would happen?