I am currently living with my wife of four years ([Moderator redacted]) and we have two young children together ("I" and "E"). I am employed in the Army and my wife is a stay at home mother. Due to the unique requirements of my job, I have had to move away from my two older children (“C” and “B”) with whom are residing in Sydney with their mother ([K]) and her boyfriend (J) in Sydney. I currently live in Brisbane. It has been hard for me as a father to hear of my children not being cared for properly over the past six years or so. I have seen a lawyer in the past and the lady stated that I was going to be fighting an uphill battle and would lose a lot of money to not win, due to a lacking of physical evidence. My ex has been very smart in the way she has done things by not reporting incidences to the Hospital or her Doctor. An example of this is, My ex and kids were at my ex's cousins two story home, “B” was playing near a window and was pushed out of the window by her cousin's son where if it wasn't for the awning breaking her fall she could have died. Background into my Ex and I. I was with her for quite a few years and in that time I got to know her family very well and also the people that they conduct their lives around. They are drug dealers and are well known with the police living their lives with no rules or boundaries. [K] is currently living in a garage at her boyfriends mothers house with "J", “C”, “B” and her three younger children as they got kicked out of their last home and are blacklisted from renting houses as they left their last house trashed. I am living in a four bedroom home and all I have to do is show proof that I have “C” and “B” in my care and I will receive a larger house at no extra cost. Facts relating to my question are 1. “C” and “B” visited us in Brisbane just after New years eve this year for approximately two weeks. 2. “C” had a skin condition on her to top of head approximately the size of a golf ball which was scaly to touch and made her hair fall out in that region. 3. I asked [K] what it was and she said that she took “C” to the Dr about it but the Dr did't know what it was and told her to see a specialist and that she was going to take her to one when the girls went back home. I then informed [K] that I would take “C” to a Dr here to get a second opinion. Our Dr then immediately took a sample of the skin tissue for analysis and we got the results back the next day. The result was tinea capitis which is ringworm of the scalp and is easily treatable however highly contagious. I will let you look into possibly why this has happened however most of the causes are due to a lack of hygiene. As soon as we new this we started treatment instantly. About five days before they left to go home. 4. Within that 5 days we noticed a very small rash on “B”'s head and we informed [K] of this and that the mark was likely the same condition as “C”. [K] acknowledged this, we gave the treatment to [K], [K] then stated that she would apply the cream as directed. Applying the cream correctly should see the condition all but gone within eight weeks. 5. It has been close to ten weeks now since I left the girls in her care. I have just found out that “C”s condition is no better and “B” now has missing hair on her head approximately the size of a tennis ball. My wife is down in Sydney currently and will be taking the kids to the Dr to get some advice on why the kids skin is the way it is. This is not only a condition that is effecting their skin and hair but also children at school are not nice regarding these matters and could scar the kids mentally as well. So my question is: In the current situation, If i get a letter from the Dr stating that [K] has medically neglected my kids, Do I have authority to seize custody of my children from her and if not, what do I have to do to get custody because this is very sad for my kids and they should never have been in this position?