Her father Brett posted on her Facebook page that the family was flown urgently to Belgrade for specialist treatment after Tahlia took a turn for the worse.

Mr Smith said Tahlia was experiencing a lot of pain from her second stem cell operation.

“She became very unwell, her stomach has been swelling very badly and her pain was becoming worse and her doctor was very concerned,” Mr Smith said.

The family is now in Belgrade awaiting the results of blood tests.

“They are thinking she could have had an internal bleed or a clot or infection,” Mr Smith said.

“A bit of a diversion in our treatment plan to get our girl home,” he wrote. 

“Hoping it’s something simple. Will know more later.”

The Mercury reported earlier this month how Hunter MP Joel Fitzgibbon had set up an online petition calling on the federal government to restore the Clinical Advisory Committee formed to investigate Lyme disease.

To sign the petition go to http://www.joelfitzgibbon.com/lymedisease