People who migrate to Australia on a partner visa still have rights. A sponsoring partner has no power to cancel their partner's visa or have them deported - even though they might threaten to do so. Only the government agency responsible for immigration can do this (the Department of Home Affairs). If you know someone experiencing domestic and family violence from a sponsoring partner, you can assure them there are provisions in the law to allow them to apply to stay in their own right.
People in Australia on a temporary visa often won't have access to the same levels of support as permanent residents and citizens. Their visa status (and type) will determine whether they can access income support from the government or free health care - among other things.
However there are organisations that can help. It is never acceptable for a partner or family member to use a person's visa status to coerce and threaten them.
If a person on a partner visa leaves their sponsoring partner because of abuse, they are required to notify the Department of Home Affairs that the relationship status has changed; this can be done online using an ImmiAccount.
There are free interpreter services available if needed when they contact the Department. Let the department know that there is domestic violence if a person is concerned about their visa status.
People on a temporary visa experiencing financial hardship because of domestic violence may be able to access financial support from the Red Cross.