Over £20 million (€28.8 million) has been stolen from a bank in central Belfast by raiders who took members of staff and their families hostage on Sunday.
The raiders made off with the money yesterday afternoon and police were alerted late last night.
Assistant PSNI Chief Constable Sam Kinkaid, who is head of the Crime Operations Department, told a news conference this afternoon the robbery took place at theNorthern Bank bank cash centre in Donegal Square West in the city centre.
He said two senior members of staff and their families were held hostage at their homes in Dunmurry on the outskirts of Belfast, and Loughinisland, Co Down. The gang went to the employees' houses on Sunday and held them hostage overnight.
The officials, both keyholders, were threatened and "coerced" into going into work the following day as usual. They were then forced into handing over the money after the bank closed. This happened between 6.30 and 8.30 p.m., Mr Kinkaid said.
The families were released last night once the gang had emptied the bank's vaults of around £20 million in Northern Irish banknotes.
At least one lorry would have been needed to ship the cash out, Mr Kinkaid said. Police tonight are examining CCTV footage from around the bank tonight in an effort to identify this vehicle.
He said it was too early to say whether or not the criminal gang involved were linked to paramilitaries. They were "clearly well-organised", however.
He also said while paramilitaries had not been ruled out, there were a number of organised crime gangs operating in Northern Ireland who are not involved in paramilitarism.
The exact amount stolen has not yet been established. "We have had to hold a (crime) scene at the bank during the day to ensure that a professional forensic examination is carried out. That has somewhat delayed the bank's ability to carry out an audit to give me an exact sum," Mr Kinkaid said.
"But on the information that I have received to date from interviewing witnesses and people who have been present at the bank early this morning, I have been informed that the sum is quite considerable and may be in excess of £20 million."
An audit is continuing tonight at the bank to establish exactly how much was stolen.
The targeted safe stored money being distributed to all 95 branches of Northern Bank in Northern Ireland in the run-up to Christmas, when banks typically handle their greatest volumes of cash.
Police say around 230 gangs are currently heavily involved in crimes such as armed robbery, drug trafficking, prostitution, extortion rackets, and counterfeiting. Many of them have links to republican and loyalist groups, who have tightened their grip on organised crime since their ceasefires ten years ago.
The taking of hostages in exchange for large sums of money has become one of the most popular tactics employed by gangs recently. Dissident republicans are believed to be behind a number of unsolved crimes, involving the use of hostages in the Strabane area of Co Tyrone.
During the summer, the INLA was linked to a robbery which netted more than £300,000 from an Ulster Bank in Strabane.
A gang subjected a bank official and his family to a terrifying ordeal, holding them at gunpoint overnight. The bank worker was ordered to go to his bank the following morning and ask his colleagues to hand over a large sum of money, or his family would be killed.
Northern Bank is the largest retail bank in Northern Ireland, with 95 branches. Last week, Denmark's Danske Bank agreed to buy Northern Bank and National Irish Bank from National Australia Bank (NAB). A spokesman for NAB, which is still running the bank during a handover period, said no staff were injured, the spokesman said.
Police said this evening they believe the gang, suspected of numbering up to 20 men, may have been working on inside information.