NATA approved paternity testing

Last year my brother was informed by an ex that he was the father of a baby girl she had given birth to 3 days earlier. They had dated for only a couple of months during the previous year and this was the first he had learned of her becoming pregnant.

Within a week the baby was admitted to RCH due to a hole in her heart and leaky heart valve. They were informed she would require open heart surgery in the coming weeks/months. My brother was asked to sign the birth certificate and felt given the circumstances, now wasn't the time to request paternity testing so he signed the birth certificate.

Fast forward a couple of months and bubs had open heart surgery at 5-6 weeks of age and was doing amazingly well. He started having her on weekends and was over the moon to finally be a father. For peace of mind he did a home paternity test when she was around 5 months old. He was devistated to learn he was not the father and he was in denial, so he did another home paternity test through a different company and it also came back saying he is not the father based on their DNA. Meanwhile during all those months it took for the results to come back, he kept having her on weekends and loving her like his own child. He paid child support, but instead of using formal avenues the Mother requested it be a bank transfer, so my brother obliged. A couple of weeks after he got the second result also stating that he was not the father he finally confronted her. She flat out denied the possibility and said that he was no longer allowed to have any contact whatsoever and she asked that he deletes all photos of her and that our family also deletes all the images we have of her. This was her immediate response to him questioning her paternity. He was also told to not contact her again and to speak with her solicitor. Meanwhile she never provided him with the name of her solicitor. A few weeks later he massaged her to ask who her solicitor was and he only was give a first name. After stuffing him around for a month of so he finally got a name only to find out that the solicitor wasn't actually representing her. Now my brother has had to seek assistance from a solicitor to go about the process of getting him removed from the birth certificate. Blood tests have to NATA approved in order for him to be removed from the birth certificate and blood must be taken from the child and both parents in order for this to happen. He believed the solicitors would be able to help recommend where/how these blood tests can be organised but they have left it up to him. So, does anyone know how you can get NATA certified blood samples done in this situation or where they can be done? She is based in Ballarat, Victoria.

Thank you!