In a delicious twist of irony, imprisoned Josef Fritzl insists on open air exercises in prison while his cellar children are slowly venturing out into the wide world outside.
Fritzl had kept his daughter Elisabeth locked in a cellar in Amstetten, Austria, and fathered her seven children before police caught him when he was forced to hospitalize one of the three brought up in the dungeon.
One of the seven died when very young, three were never allowed to leave the cellar even for a minute, while the other three went on to live with Fritzl as his adopted or fostered children.
Elisabeth, her children and her mother are getting treatment and counseling at a psychiatric clinic guarded by police since late April.
One of the children who lived upstairs — a 15-year-old girl — spent last weekend "incognito" at a youth fire brigade camp with 4,000 other youngsters and met up with some of her school friends for the first time in nearly three months.
Other family members also have made day trips outside under disguise, the Kurier newspaper reported.
Elisabeth has been questioned by prosecutors for the first time, it has been reported.
The Austria Press Agency, citing unidentified judicial sources, said 42-year-old Elisabeth Fritzl was interviewed Friday in a secret location.
Film of the interviews will be shown in court at the father's trial later this year, Austrian media reported.
Fritzl himself has been making copious notes ready for the interview, as he will be present when Elisabeth speaks via a video link up and will be allowed to ask questions via his lawyer. And the man who locked away his daughter in a windowless cellar for 24 years, has asked permission to leave his prison cell, saying he can no longer stand being cooped up.
Prison spokesman Lieutenant Colonel Erich Huber-Guensthofer said: "Mr Fritzl is accommodated in a cell for two and recently he has made use of his right to go outside for half an hour per day.
"He usually sits there watching television all day, especially news programmes about him," said one prison source. "He's terrified that someone will attack him or try to kill him."