London, May 3 : Two of Elisabeth's kids - the woman who was held captive by her father and gave birth to his seven children - have symptoms of confinement last seen in World War II prisoners, a nurse revealed on May 2.
The nurse claimed that Stefan, 18, and Felix, six, were restless and confused, suffered nightmares and made sudden, jerky movements.
Felix, who has a "monkey-style" walk, also makes "shuttle runs" across the room.
On May 2 medics at Amstetten-Mauer hospital, Austria, said their sister Kerstin, 19, was not expected to live after suffering multiple organ failure.
"Her chances are very low," The Sun quoted a rep, as saying.
If she dies Fritzl, 73, may be charged with murder by neglect.
He fathered seven children by daughter Elisabeth, now 42, whom he locked in a cellar for 24 years.
The three kids kept in the cellar have anaemia and "papery skin" from the lack of sunlight and fresh air. Stefan and Kerstin also have few teeth.
The hospital nurse said of the boys: "They are lovely children but have nightmares and call for their mum.
"Specialists who worked with PoWs say the pair have classic post-traumatic stress symptoms," the nurse added.