The would-be robbers who targeted HSBC Centre in Qormi on Wednesday entered the building through a side entrance which needed an electronic code known only to employees.
The element of surprise was so effective that they managed to disarm a special assignments group policeman -- described by police sources as one of the section's best - who was stationed at the main door of HSBC's Qormi headquarters.
The three men, who were accompanied by at least a fourth manning a getaway car, walked into the building wearing wigs and fake moustaches. They ambushed the officer, removed his issue pistol and tied him and two employees with cable ties.
The knowledge of the electronic code, together with their familiarity with the maze of hallways leading to the centre's control room, have convinced investigators the men were in possession of inside information.
"Anyone who was unfamiliar with the headquarters would probably get lost inside," the sources said.
The robbers were targeting one of the bank's underground vaults, where millions of euro from the branches pour in every day for safekeeping. They managed to reach the control room from where they could open it.
Everything seemed to be going smoothly for the robbers until a neighbour informed the police about suspicious activity going on near the bank at about 7.30 p.m. A patrol car was sent to the area but when it got there a car parked outside HSBC's Windmill Street headquarters sped off, leading officers into a chase.
The three robbers, however, were still inside and in the meantime someone in the building, who the thieves had apparently not accounted for, called for help.
The patrol offers were asked to return to the site but as the two policemen were running up the steps leading to the banking centre they almost came face to face with the robbers. That's when the shootout, likened yesterday to something out of the Wild West, erupted.
The officers were forced to take cover behind some trees, eventually inching their way towards the cars on the street for better protection.
As the shooting went on, a getaway car (different from the first) rushed into the shootout and sped off again with the robbers on board. The police shot at the vehicle but failed to stop it.
Investigators yesterday focused on collecting forensic evidence and interviewing bank employees.
Among the evidence collected was a bottle of fuel which at first was thought to be Molotov cocktail but then turned out to be filled with the less flammable diesel which, more likely, would have been used to hinder a chase by spilling it on the tarmac.
The bottle was found together with a briefcase containing cable ties, a pistol and a wig.
Sources said the holdup follows recent instructions issued by the police to all patrols to keep a close eye on cash points and escort any security vans they come across.
The police are not excluding that Wednesday's job could have been carried out by the same gang that stole a million euro from HSBC's Balzan branch three years ago.
In that incident, hair found attached to a balaclava that was left behind was later found to be synthetic - a clever attempt to deviate investigations. Similarly, in this case the police are suspecting the wig and other items left behind could be decoys.
Investigations are being headed by Inspector Sandra Zammit from the Qormi District Police and Inspector Anthony Portelli from the Criminal Investigation Department.
A magisterial inquiry is being carried out by Magistrate Claire Stafrace Zammit, assisted by ballistics expert Brigadier Maurice Calleja, architect Richard Aquilina and serologist Marisa Cassar.