The rucksack bomb that killed 22 people in Manchester was so complex that it could only have been made by an expert, leaked crime scene pictures suggest, as it emerged that an al-Qaeda bomb-maker lived on the same street as suicide attacker Salman Abedi.
Photographs of bomb remnants found at the Manchester Arena show a trigger switch with a tiny circuit board soldered into the end, which experts say could point to a remote-control or timer built into the bomb to ensure an accomplice could detonate it if Abedi lost his nerve.
Investigators believe the bomb, packed with bolts and screws, was contained in a lightweight metal case carried in a black Karrimor rucksack with a blue lining.
They also found the remains of a specialist 12 volt battery that is more powerful than high street brands of battery used in previous attacks.
The crime scene photographs were leaked to the New York Times after being shared with US intelligence, prompting a furious response among ministers.
Amber Rudd, the Home Secretary, had publicly asked US law enforcement agencies to stop leaking shared intelligence and said she had been “very clear with our friends that that should not happen again”.
She said the leaks had been compromising the fast-moving investigation into what police have described as a “network” behind Abedi, but her warning was ignored as the extraordinary series of pictures were leaked in the US, prompting a major diplomatic row.
A senior Whitehall source told The Daily Telegraph: “These leaks from inside the US system are likely to deeply distress the victims, their families and the wider public. Information has also been leaked which risks compromising the ongoing investigation into this appalling crime.
“Protests have been lodged at every relevant level between the British authorities and our US counterparts. They are in no doubt about our huge strength of feeling on this issue. It is unacceptable.”
The Telegraph understands that Theresa May will raise the matter with President Donald Trump when she meets him at a Nato summit in Brussels today.
Among the details leaked to the New York Times was a diagram of where the dead had been found, with most of them forming a circle around the point of detonation. Scenes of crime experts suggested the pattern showed that the bomb had been tightly and evenly packed with explosives and shrapnel.
Abedi’s upper torso was found some distance away from where the bomb went off, suggesting it was thrown forwards when the bomb went off on his back. A gap in the circle of bodies around him suggests his body shielded those directly in front of him from the worst of the blast.
The newspaper was also briefed that the trigger device, which appeared to be housed in a brass casing, had been held in Abedi’s left hand. A tiny circuit board and a red wire poking from one end of it could have been part of a remote control or timer system, and suggest a far higher level of sophistication than the simple thumb switches and light bulbs used in the 7/7 attacks.
The final bomb component, identified by the remains of its label and casing, was a Yuasa 12-volt, 2.1 amp lead acid battery costing around £12. Sometimes used to power emergency lighting, it has the appearance of a small car battery and is more powerful than ordinary batteries.
Nuts and screws used as shrapnel, photographed lying on the tiled floor of the foyer, had travelled with such force that they penetrated metal doors and left deep gouges in brick walls.
The evidence helps to explain why the security services are so convinced Abedi was part of a wider terrorist cell, as the level of expertise needed to build such a device points to an expert bomb-maker who could still be at large.
The Daily Telegraph can reveal that an al-Qaeda bomb-maker who fled to Libya lived in the same street as Abedi and that the security services are probing possible links between the two.
Abd al-Baset Azzouz was identified as one of the world’s most dangerous terrorists by US authorities after setting up a training camp in Libya.
Both the Azzouz and Abedi families lived in the same street in Wilbraham Road in around the year 2000, according to records seen by The Telegraph.
After that they lived in homes never more than about a mile from each other as part of a tight-knit community of Libyan dissidents opposed to the tyrannical rule of Colonel Muammar Gaddafi.
Security sources say police are investigating whether Abedi could have been supplied with a bomb made by Azzouz, or else taught to make one by him.
Azzouz was a prominent member of the Libyan Islamic Fighting Group (LIFG), a banned terrorist group, during years spent in exile in Manchester. Salman Abedi’s father Ramadan Abedi was also named yesterday as a one-time member of LIFG in Manchester.
Security sources have told The Telegraph they are probing Abedi’s movements in Libya, and whether he met Azzouz.
Azzouz, 50, a father-of-four, was arrested in the UK in 2006 by counter-terrorism police before being freed on bail.
He left the UK in 2009, travelling to Pakistan and Afghanistan where he became a close lieutenant of Ayman al-Zawahiri, Osama bin Laden’s successor as leader of al-Qaeda. Questions have been raised over why he was allowed out of the country to reach a terrorist training camp and whether he was ever released from bail.
Two years later, Azzouz returned to his homeland in Libya, running al-Qaeda operations there. US authorities said in 2014 he was training 200 to 300 militants and described him as an expert in bomb-making.
A UN terror designation list published last year linked Azzouz to both Islamic State and to al-Qaeda and suggested he was operating in the eastern part of Libya, which was an Islamic State stronghold.
Salman Abedi had made a number of trips to Libya in recent years and was there as recently as the start of this month.
Intelligence agencies and counter-terrorism officers are also exploring possible connections between Abedi and a group of Manchester jihadists who travelled to Syria to join Islamic State in 2013.