Austrian authorities say a man accused of imprisoning his daughter as a sex slave for 24 years will probably go on trial next year.

Officials say they are still preparing the indictment against suspect Josef Fritzl, but time is running out for a trial to start before Dec. 31.

Prosecutor Gerhard Sedlacek says investigators are still gathering statements and other evidence against the 73-year-old Fritzl. Police say he imprisoned his daughter — who is now 42 — when she was 18, and fathered her seven children.

Sedlacek said Monday there's still a chance the trial will begin in December, but that it seems more likely the proceedings will start early in 2009.

Fritzl released his victims in April.