Adding Secondary Applicant 457 - Defacto

Hi,

Im current holding 457 visa in Qld and would like to add my partner as a secondary applicant.

The problem is I’m still legally married (overseas) to someone however that relationship has finished and I have not divorced due to family issue.

I’ve met my current partner in Oct 2016 and moved in together since March 2017 since then we’ve been living together.

I would like to know if it’s possible to add my partner as secondary applicant to my visa and what’s the process? Can we stand a chance to register as defacto to be able to get through this?