Even as he languishes in solitary confinement in a prison that fittingly was once a Nazi concentration camp, Anders Behring Breivik continues to wage his demented war against Islam.

Having murdered 77 innocent victims, he is now entering the propaganda phase of his 21st-century crusade. Confined to his cell, The Sunday Telegraph has learnt that he spends his waking hours writing speeches or making bizarre requests to the authorities.

“He wanted to get caught. He has admitted everything. He wrote [in the manifesto] that the propaganda phase starts at the arrest.”

Another former schoolfriend told The Sunday Telegraph that Breivik’s attention-seeking was evident a decade ago. “I remember we were at a party,” recalls the former friend, “and he told me he had had his nose and chin operated on by a plastic surgeon in America. It was a bit weird, but he was hanging around at that time with a group of people obsessed by their bodies.”

For Breivik – even at the age of 21 – a nose job was the logical next step in his desire for physical perfection.

He had a drastic solution, too, for curing what he saw as the ills of multicultural Norway. He would slaughter government workers and the children of the Norwegian socialist elite as the opening salvo in a new crusade against what he perceived as the creeping Islamification of western Europe. His plan was laid down in his manifesto, 2083: A European Declaration of Independence. The year 2083 signals when Breivik was convinced the civil war he hoped to start would be over.

The manifesto – part war manual, part propaganda text – offers an astonishing insight into Breivik’s own private life and those around him. Except that last week, The Sunday Telegraph tracked down some of the key figures in the manifesto, who debunked large parts of the life story he has claimed for himself.

What is true is that Breivik was born in London in February 1979; his father, Jens, was an economist with the Norwegian embassy, his mother, Wenche Behring, a nurse. But within a year, the couple had split and Breivik and his mother returned to Oslo while Jens stayed in London. They found an apartment on a smart housing estate in a well-to-do suburb of west Oslo, where Breivik lived until he was 15. “I feel I have had a privileged upbringing with responsible and intelligent people around me,” Breivik wrote of his early childhood. “I do not approve of the super-liberal, matriarchal upbringing, though, as it completely lacked discipline and has contributed to feminise me to a certain degree.”

Today, the three-storey apartment block, occupying one side of a square, remains home to many young families. A sandpit occupies the centre of the square while unlocked children’s bicycles are parked beside it. In one corner, mourners have placed flowers and candles in remembrance of the victims of the neighbourhood’s now most notorious former resident.

“I never felt comfortable with him. He was a little cold, although I never thought he was crazy,” says Lina Engelsrud, who lived in an apartment close by. “He used to spit in the basement and pee in the neighbour’s shed. He took great pleasure in killing ants.”

Linn Roodla, 21, who grew up in the estate, says: “It is weird he came from here. It’s completely middle class. There is no reason for him to be angry, growing up here.”

By the age of 12, Breivik claims to have become one of Oslo’s “most notable” street dancers and that by 14 his was the most recognisable graffiti “tag” in the capital. His abilities, he wrote, earned him the admiration of teenage girls but the wrath of his father, who never talked to him again after his son was caught by police.

His father has said he wishes Breivik had shot himself on Utoya island. A schoolfriend at the time – who did not wish to be identified – says: “It’s true he got into a lot of trouble, but what he doesn’t admit is he informed on his friends to the police. When it comes to depicting himself, not all of that adds up – like his claim to be the best-known graffiti artist in Oslo.”

In his manifesto, Breivik says several of his friends were Muslims, including a boy called Faizal Rafique, and that he had spent his time with a gang of Pakistani boys, whom he later accused of robbing and intimidating white children.

Tracked down by The Sunday Telegraph, Mohammad Rafique, Faizal’s father, who still lives on the estate, paints a different picture. His son was younger than Breivik and barely knew him. “He has tried to turn opinion against Muslims by killing his own [Norwegian] kids,” says Mr Rafique, recipient of a medal from the Norwegian royal family for service to the car industry. “Why would he do that to innocent children? There was never any tension here. When he was growing up he had no problems.”

Breivik says his closest friend was a boy called Arsalan, but the pair fell out when they were 16. He accuses Arsalan and other Pakistani youths of being violent and claims to have been beaten up eight times, once suffering a broken nose; it is the moment Breivik claims he railed against multiculturalism. “At the time, I couldn’t understand why he [Arsalan] loathed Norway and my culture so much,” wrote Breivik. “I was completely ignorant at the time and apolitical, but his total lack of respect for my culture… actually sparked my interest and passion for it.”

It is a claim disputed by Arsalan’s family. His father, a wealthy doctor, was too upset to talk last week about the claims. The family are terrified of being dragged into the mire. But a family friend said: “Arsalan hasn’t known him [Breivik] for 25 years. They were only at primary school together. Arsalan can’t be blamed for what Anders Breivik has done. It is ridiculous to blame Arsalan for making him angry about multiculturalism. Arsalan and his family have integrated here.”

Whatever the truth, Breivik’s views became increasingly extreme. He eschewed university and instead continued his education “informally”. He claimed to have earned a fortune investing in the stock market but lost millions of krone in a “correction” – another manifesto claim that a friend disputes.

In 2002, aged 23, Breivik writes of travelling to London to establish with other extremists the Knights Templar, a new crusading movement to crush Islamists. No extremist has come forward to admit being at the meeting, although Paul Ray, a founder member of the anti-Islamist English Defence League, admits he may have influenced Breivik’s thinking.

From then on, Breivik secretly plotted his attacks. His strategy in place, it’s not clear how he funded his enterprise but money appears to have been no great problem. By now claiming to be a committed Christian, he held a number of minor posts in the far-Right, anti-immigration Progress Party but abandoned conventional politics in 2003 after losing an Oslo City Hall election.

He was close to a small group of friends throughout his twenties and early thirties and lived a bachelor’s life in Oslo, going to the gym and latterly joining an Oslo gun club and the freemasons.

None of those friends – identified only by first names in the manifesto but with enough information given to piece together who they are – would talk about Breivik. One is a government lawyer, another a commercial property agent and a third a fireman.

There is no suggestion any of them knew what he was planning, but all will now be seriously embarrassed by their association with him. Authorities will want to know what – if anything – they suspected of Breivik’s activities.

In 2009, Breivik set up a “biofarm” company, buying a farmhouse north of Oslo as perfect cover for his bomb-making factory. He would order six tons of highly explosive, artificial fertiliser without ringing alarm bells.

He moved out of his own flat in Oslo and back in with his mother at the age of 30 to save money. By now he was taking steroids to beef himself up, even detailing changes in his weight in the manifesto. He would sell his possessions – a designer watch, furniture and paintings – to fund the terror attacks. He played computer war games to simulate the attack he was about to instigate and grew apart from his social circle back in Oslo.

He found time in his manifesto to list his favourite things: his Breitling watch, his iPod, a certain men’s cologne. Even Lacoste clothing gets a mention. Peter Svaar, who was friends with the young Breivik, is struggling to come to terms with what has happened.

“What keeps me awake at night is not that he’s a monster,” says Mr Svaar, “it is that he is a regular, Norwegian boy.”