St Poelten, Austria  - The jury in the case of Josef Fritzl, the Austrian man accused of imprisoning and raping his daughter Elisabeth for 24 years, and the murder through neglect of their baby boy, retired to consider its verdict on Thursday morning.

Fritzl had the final word before the jury retired, saying he now regretted his self-confessed crimes.

"I regret with my whole heart what I did to my family. I can unfortunately not make it better again. I can only seek to reduce the damage if possible," he said.

In the final statements to the jury, the prosecution called for a sentence of life imprisonment for murder through negligence, arguing that Fritzl had deliberately allowed Michael, who was both his son and grandson, to die in the dungeon when he was born with a life- threatening illness in 1996.

"For this he deserves the highest sentence," prosecution lawyer Christiane Burkheiser told the jury.

The defence lawyer rejected the murder charge and asked the jury to show sympathy for Fritzl, adding that the 73-year-old "will go to prison for 20 years anyway."

Fritzl had unexpectedly changed his pleas on Wednesday, to confess to all the charges, including murder and slavery.

Fritzl is now apparently being kept on suicide-watch, according to TV reports.

German n-tv television reported Thursday that Fritzl was placed in a cell with another inmate to keep an eye on him, and has had his shoelaces removed.

A verdict is due Thursday, once the 8-strong jury have deliberated on a list of questions prepared by the judges. Four reserve jury members are on standby in case of illness or other incapacity.

If convicted of murder, Fritzl faces lifelong imprisonment.

An expert psychologist recommended to the court that Fritzl should subsequently be admitted indefinitely to a facility for abnormal offenders, should he be handed a finite sentence.