Police confirmed today that approximately £22 million (€31.5 million) was taken in Monday's raid on the Northern Bank in Belfast .
However, the gang may find it close to impossible to dispose of their haul as around £13 million of it is in new Northern Bank notes.
Police said £12 million in new Northern Bank £10 and £20 notes as well as £1.15 million of £100 and £50 were among the stolen cash. Police said they also have some of the serial numbers.
Detective Superintendent Andy Sproule said: "This was a carefully-planned operation by professional criminals who obviously had done their homework."
A team of 45 detectives are working on the case. They are examining footage from cameras inside and outside the bank just off Donegall Square in the heart of Belfast city centre. They are also examining a burnt-out car found in a remote forest in Co Down.
It is believed the car was used by the gang to abduct a family member of one of the bank's senior workers. The woman was freed in the forest at Drumkeeragh near Dromara, about ten miles from her home.
The police officer in charge of the investigation could not say whether any paramilitary grouping was associated with the meticulously planned robbery. Assistant Chief Constable Sam Kinkaid left open the possibility that the robbery could have been carried out by a criminal gang with no paramilitary connections.
"We don't know, it's a possibility. It could be paramilitary related." He added: "This was not a lucky crime, this was a well-organised crime." The raid is one of the largest robberies ever carried out in Britain or Ireland.
Last night a police source said all lines of inquiry, including the possibility that the gang used inside intelligence, were being followed.
Gunmen arrived at the home of two senior Northern Bank officials at 10 p.m. on Sunday, one in Dunmurry just south of Belfast, the other at Loughinisland, a hamlet near Ballynahinch, Co Down.
Two gang members posed as PSNI officers at the front door of Mr and Mrs Kevin McMullan's Loughinisland home. They said a relative of the McMullans had been injured in a road accident. When invited inside, the gang pulled a gun and threatened the couple.
Mr McMullan, who is in his early 30s, was ordered to leave for his office and to work normally throughout Monday until the staff went home.
It is understood a similar ploy was carried out by gang members at the home of the second senior official in Dunmurry at the same time.
Between 6.00 p.m. and 8.15 p.m. the underground vaults were plundered. Cash was bundled into containers, stacked into wire cages and taken out in two separate runs to a waiting white box-type van with a specially-fitted tail lift.
The truck drove off from the headquarters on Donegall Square West towards the West Link, a major motorway route running through the centre of Belfast.
The operation took two hours to complete before the cash, much of it in distinctive Northern Ireland banknotes, was driven off.
It emerged this morning that the bank's parent, National Australia Bank (NAB), had no external insurance policy to offset the losses and would bear the cost itself.
But the owners insisted the robbery would have no knock on effect for the sale of the Northern to the Danish Danske Bank Group announced earlier this month. A statement from the bank said: "The theft is covered by self-insurance, and as such, National Australia Bank, which currently owns Northern Bank, will bear the impact of any losses arising from the theft."