The evil father who locked up his daughter in a cellar for 24 years and fathered her seven children was pictured on a 'boys holiday' to Thailand in the 1990s, it has been revealed.
Josep Friztl is believed to have stockpiled food in the dungeon where Elisabeth and her three children were being held.
The four were expected to survive alone for up to two weeks until Fritzl returned. Snaps of the electrical engineer enjoying himself were made public for the first time today.
They come as it was revealed that Fritzl has told police he acted alone.
He has told detectives he was not helped to keep his Elisabeth and their children hidden in his cramped basement.
But police are not yet convinced he is telling the truth and are investigating how he could have bought food and clothes for them without anyone suspecting.
The 73-year-old pensioner, who has now been confirmed as the father of all Elisabeth's children, was today remanded in custody for two weeks.
Relaxed: Incest father Fritzl on holiday
At a press conference in Austria after the brief hearing, police said: "He is saying that he worked alone, that he acted alone, in making sure his daughter was kept in that cellar but the authorities are not sure that is what happened.
"As a result they are now carrying out further inquiries. They want to know where the food came from to look after those children and where the clothes came from."
Experts have dubbed Fritzl a "ruler" who must have been mad to have carried out such a campaign of abuse against his own family.
Austrian psychiatrist Reinhard Haller said he appears to have been motivated by pronounced narcissism and a drive to exercise his control over others.
He said: "This man must have been insane and must have felt he was far superior to others."
Court psychiatrist Sigrun Rossmanith said Fritzl essentially had two personalities - "the underground one, and the one that existed above".
"He was obviously a ruler. If the cellar was taboo for his wife and children, and they heard that over and over, then they didn't dare to check on anything," she said.
"If someone has power and forces it on someone else, then his word is like the word of God."
The pensioner has not yet shown any remorse for his actions, according to prosecutor Gerhard Sedlacek.
At today's hearing, Mr Sedlacek said Fritzl was "completely calm, completely without emotion".
But his lawyer, Rudolf Mayer, said: "He is really hit by this. He is very serious, but he is emotionally broken.
Asked whether he showed any remorse, he added: "I cannot say at this point."
The revelation today that Fritzl had a criminal record will increase the anger that his behaviour could have gone undetected by social services for almost a quarter of a century.
It also indicates his wife Rosemarie must have been aware - at least to some degree - of her husband's sinister side.
Incredibly, it is still claimed she knew nothing about the secret dungeon beneath her home and the unimaginable horror going on under her nose.
Police in Amstetten are now trying to unravel why Fritzl, 73, was driven to lock up his daughter and subject her to decades of abuse.
The retired electrician faces charges of incest, abduction and imprisonment and could serve 15 years in jail if convicted.
He appeared in cout today in St Poelten, the provincial capital of Lower Austria, and was detained in investigative custody for two weeks.
During the brief hearing, the pensioner said nothing to the magistrate.
Prison officials said the pensioner was calm last night but that he had been placed in a large, two-person cell as a precaution to try to stop him killing himself.
Investigators were searching the 60-square metre cellar beneath Fritz's two-storey home today.
Forensic experts in white uniforms and gloves have been carrying out boxed of evidence from the building, which is on a busy street with shops and also home to several other families.
"Down there it is just chaos at the moment. We have to go over every detail very carefully," Franz Prucher, head of security in Lower Austria, said.
Police are desperate to determine how Fritzl's victims could have been hidden away for so long from their neighbours and everyone else in the town, which has a population of just 23,000.
They are said to be examining the padded walls of the cellar to work out whether the children's screams could be heard by neighbours.
Neighbours have told police they heard nothing but many are incredulous that they could have failed to spot anything unusual, not least because over the years Fritzl had built extension after extension to his cellar.
"The community of Amstetten should drown in shame ... The neighbours are turning a blind eye," the Oesterreich newspaper wrote in an editorial.
Meanwhile, residents refuse to believe Fritzl could have acted alone, while others cannot believe that the "normal" family were hiding such a horrendous secret.
Anita Fabian, a teacher in the town, said: "How is it possible that no one knew anything for years? This was not possible without accomplices."
Guenter Pramreiter, who owns a bakery down the street from the Fritzls' home said the couple were regular customers.
"They appeared normal, just like any other family," he said. "I'm totally shocked. This was next door. It's terrible."
Yesterday, Austrian police released details of Fritzl's secret family and the life he forced them to lead in the cramped cellar beneath his home.
His daughter Elisabeth had seven children in all during her 24 years in incarceration, all of whom were delivered by her father at their house.
Police said that when she had twin boys 12 years ago and one died, Fritzl merely tossed the body in a furnace used to heat the grey concrete villa.
He raised three of the children with his 60-year-old wife Rosemarie, while the remaining three lived with their mother behind a steel security door in the basement.
Apart from 42-year-old Elisabeth, he and Rosemarie had another six children of their own, now all grown-up, making him a father of 14.
Chillingly, details have emerged of a second house owned by Fritzl a mile away. It, too has an excavated cellar with stone bath and a 3ft hacksaw on the wall.
The man police described as "dynamic, bossy and authoritarian" faces up to 15 years in prison if convicted of raping his daughter. His victims and wife are receiving psychiatric care at a secret location.
Her oldest child, 19-year-old Kerstin, was still fighting for life in hospital last night. It was her arrival there, suffering from a mystery condition, which led to the discovery of the cellar dungeon.
But the youngest of the freed children, five-year-old Felix, told carers of his joy at the simple pleasure of riding in a car after spending his entire life underground.
"He said how happy he was and how fantastic it was to ride in a real car," said Heinz Lenze, the local mayor.
Mr Lenze says he is convinced that Fritzl acted without his wife's knowledge.
"Is it possible she knew?" he asked. "For me it is beyond imagination that she would knowingly put up with her husband having a new family with their own daughter."
Rosemarie apparently accepted her husband's explanation that Elisabeth had run off to join a religious cult at the age of 18 - and that over the intervening years dumped three babies on their doorstep with notes saying she could not cope.
She and her husband formally adopted the three children - Lisa, 16, Monika, 14, and Alexander, 12 - bringing them up as their own.
The three were apparently unaware of their mother's existence, let alone that their siblings Kerstin, 19, Stefan, 18, and Felix were living below them.
It remains a mystery why Fritzl allowed three children to live a relatively normal existence while the others were kept locked up behind a steel doorway.
Neighbours said the three kept above ground were well-balanced and polite members of the police sports club and voluntary fire brigade.
Their grandmother, according to many, was a pillar of the community, baking cakes for fetes and becoming an active member of the parent teachers' association at their private school.
One of his sons by Rosemarie has told police that he was "tyrannical" and a "very controlling" man who even in his older years ruled the house with a rod of iron.
Franz Polzer, who is heading the police investigation, said Fritzl was "an extraordinarily sexually potent man".
He added: "If you look at him today, you would hardly believe he was capable of doing these things."
Asked why he thought the four in the cellar had not tried to escape over the years, the detective said they were all physically weak.
"You have to put yourself into the situation of these people. They led a completely different life to ours, they do not know what we know. These children were born into the jail, they knew nothing else."
Elisabeth told police that her father began sexually abusing her when she was 11 and some years later, on August 28, 1984, he sedated her, handcuffed her and locked her in the cellar. When she became pregnant, he delivered the babies.
Social workers admit regularly seeing Josef and Rosemarie Fritzl after they adopted three of Elisabeth's children but insist they had noticed nothing unusual during routine visits.
Jiosef Schloegl, who had responsibility for the adopted children, admitted that rules had been broken because they had been formally handed over to Fritzl without the approval of their missing mother Elisabeth.
He conceded that there had been questions over the whole procedure at the time but it had been finally approved after they found no irregularities.
At Fritzl's other property in the town, 80 miles west of Vienna, neighbours said he bought it several years ago and had initially planned to demolish it and build an office block but planning approval was rejected.
One said: "You would see him two or three years ago with the children and they would play in the garden. Sometimes you would see Josef's grown-up children there too."
News of Fritzl's sickening quarter-century of abuse has stunned a nation still shocked by the scandal of Natascha Kampusch, who was held captive by a paedophile for eight years in a Vienna suburb.
Miss Kampusch yesterday offered to help the victims, saying: "I can imagine that it is very difficult both for the mother of the children as well as for the wife of the perpetrator to get through this."