Armed robbers could end up with sticky fingers after a security firm invented a cash box which fires exploding glue over the money when it is broken into.
G4S Cash Solutions has started using the boxes - which make the money inside unusable - in a pilot scheme in London.
Detective Chief Superintendent Graham McNulty, head of the Flying Squad, said: "I never want a crime to happen but we do want to see if it works."
There have been 167 cash-in-transit robberies in the city since April.
And last year there were 485 such robberies.
Mr McNulty said existing cash boxes emitted a vivid dye over the money inside if they were broken open by robbers.
But he said although the dye meant the police could track down robbers it didn't stop criminals from using the damaged money in machines or laundering it in other ways.
He said the new system should make all the stolen cash "dead money" and therefore reduce the motive for such robberies.
Mr McNulty said they were hoping to cut cash-in-transit robberies to the levels of bank raids. Last year only 10 banks in London were robbed and in four of those cases the criminals went away empty-handed.
Kevin O'Connor, Risk Director with G4S Cash Solutions (UK), said that extensive trials were taking place.
"Our tests show that the glue will ensure that an attack on a G4S cash box will be completely worthless to the perpetrator.
"Glue is the latest in a series of hi-tech solutions we have developed to reduce the number of attacks on our crew and vehicles."
If successful the new boxes could be used all over the UK.
Mr McNulty said that a number of other ideas were being tried out such as providing security guards with extensive training on how to watch out for suspects.
He said: "Last week one of the cash-in-transit crews was delivering to south London. They identified someone acting suspiciously and they contacted the control room, who were able to follow him on CCTV.
"He was joined by another man and they went on to carry out a knifepoint robbery in a shop. Flying Squad officers arrived on the scene and arrested both suspects."
Detective Superintendent John Kielty said the Flying Squad had also given presentations to 3,500 students in colleges around London to warn them of the risks of being lured into such robberies.
He explained how young people were often recruited and paid very small amounts of money.
"In one case we arrested two lads who were still in their school uniform," he said.