London, Aug 7 (ANI): Austrian incest fiend Josef Fritzl’’s crimes may never be known to the public because his trial will be heard in secret, it has emerged.

Daughter Elisabeth, 42, will testify against 73-year-old Fritzl behind closed doors to protect the six surviving children she bore him.

Elisabeth, who was imprisoned as a sex slave for 24 years below the family home, has already given a full statement to Austrian prosecutors about her ordeal, but her children have not, reports the Mirror.

Prosecutors are investigating whether it is possible to spare them the ordeal and if Elisabeth’’s testimony is enough to lock up her father for the rest of his life.

Meanwhile, according to prosecutors, Fritzl who imprisoned his daughter in a cellar for 24 years and sexually abused her may be charged with slavery and murder. (ANI)