For two long and intensely frustrating weeks after bombs tore through Bali’s nightclub strip, investigators had no idea who was responsible for killing 202 people, including 88 Australians.

What happened next has remained a secret for two decades — but it involved the shard of an exploded Nokia phone, Australian spies and their secret supercomputer.

Three bombs had been detonated shortly after 11:08pm on Saturday, October 12, 2002. The first exploded at Paddy’s Bar in Kuta, followed by a second massive blast at the Sari Club across the road.

The detonation of a smaller bomb outside the US consulate in Denpasar betrayed an anti-West motive.

“The crime scene was what you’d expect from a bomb blast,” remembers Mick Keelty, who was Australian Federal Police commissioner at the time of the Bali bombings.

“There were bits and pieces of human flesh blasted into walls. Most of the buildings had lost their roofs. There was an engine of a motor vehicle on the second floor of a building that was three blocks away from the blast.”

“A bomb attack of that scale, it shocked every one of us,” then-head of the Indonesian National Police (POLRI) General Da’i Bachtiar said.

“Even [Indonesian] president Megawati [Sukarnoputri] came to Bali to witness the extent of the damage firsthand.”

On the Monday after the attack, the president held a cabinet meeting, where almost every minister criticised the Indonesian National Police for failing to prevent the bombing.

The Indonesian general fronted ministers and prepared himself to be sacked.

“Megawati gave me my chance to speak,” Bachtiar told the ABC.

“I said, ‘Police have two main tasks: to prevent a crime from happening, and secondly to investigate a criminal case until we find the perpetrators. As the chief of POLRI, I failed my first task, but there is a second one waiting for me.'”

The pressure on Bachtiar was immense. He vowed to resign if he did not bring the bombers to justice.

General Bachtiar phones a friend

The bombsite was still smouldering when then-commissioner Mick Keelty was woken by calls from Indonesia.

“[Bachtiar] asked me how soon I could get some people on the ground,” said Keelty, who had already established a trusted relationship with the Indonesian general years before the Bali attack.

By sheer coincidence, AFP specialists were already en route to Jakarta to run a training course on the night of the Bali bombings, after Bachtiar had confided to Keelty over a round of golf in Perth, months earlier, that Indonesia lacked expertise in forensic investigation. 

The specialists were quickly diverted to Denpasar, joining other AFP officers who were in Bali already.

Operation Alliance began, led on the Australian side by assistant commissioner Graham Ashton, and on the Indonesian side by Made Mangku Pastika, who Keelty also knew well, having trained with him in the 1980s.

‘The answer will come from the skies’

Even with some of the world’s best forensic investigators onsite, the Bali bombing was proving immensely difficult.

The Sari Club blast was so big it had left a deep crater that had filled with water. And there was also a question of culture: In keeping with the Muslim faith, Indonesian authorities wanted to remove the bodies for burial within 24 hours.

After a fortnight of frustration, the only solid leads that Pastika and Ashton had to offer were a white mini-van that was used to carry the Sari Club bomb — its chassis and engine numbers filed off — and the probable ingredients of the explosives used.

Pressure was mounting on investigators.

And after meeting with Indonesian spy chiefs in Jakarta alongside ASIS director-general Allan Taylor and ASIO boss Dennis Richardson, Keelty believed Pastika’s team was being poorly advised by Indonesian intelligence.

“Their briefings did not match what we were getting from the crime scene, their briefings were way off,” Keelty said.

It was clear this investigation required some special detective powers.

“Pastika knew this already — he’d looked in the skies and said, ‘The answer will come from the skies,'” Keelty said.

“I knew that he was a practising Hindu … he prayed every day. And I said, ‘You mean from God?’ and he said, ‘No, no, no: from satellites.'”

Clues hidden in a seismogram and a Nokia

Luck changed for investigators when forensic crime scene examiner Sarah Benson found the tiny fragment of a Nokia 5110 mobile phone outside the US consulate. This was the smallest of the three bomb blast sites — and the most forensically clean.

Luckier still, that fragment contained the Nokia’s 15-digit serial number, or IMEI number.

“The IMEI number is unique to each mobile phone,” Keelty said. “You can change SIM cards on phones but the IMEI number remains the same.”

Nokia 5110 phones had been used by terrorists elsewhere in the world because they were known to produce sufficient electric charge when they rang or received a text message to set off explosions.

Knowing who owned