After two witnesses came forward police were able to track the robbers down, 200 metres from Austria’s border with Hungary – and found the cash hidden in cartons of washing powder.

They arrested a 36-year-old and a 40-year-old Romanian man, together with the older man’s 22-year-old girlfriend.

One witness said he had seen a VW Golf with a Vienna number plate parked for hours outside the bank in Marchtrenk, but had noticed that the car’s occupants did not get out. He thought they were behaving suspiciously so he made a mental note of the number plate.

When he heard about the robbery – in which the drivers of the armoured car were threatened at gunpoint and left tied up in the bank – he immediately informed the police.

The second witness was a driver who was almost rammed by the crooks’ car as they sped onto the motorway near Wels.

"Whilst we were evaluating this information colleagues from Lower Austria told us that they had already been observing this car in connection with a series of break-ins," said Ferdinand Jung, from the Upper Austrian state police. Lower Austrian police knew that the suspects were staying in hotels in Vienna – and promptly discovered the getaway car.

"During our investigation we became aware of a Romanian Audi A4, and we suspected that the suspects were preparing to leave the country in this car," police chief Gottfried Mitterlehner said.

Police followed the car and arrested the suspects close to the Hungarian border. The 40-year-old man has already served four years in an Austrian prison.

Initially police thought they might have made a false arrest as they didn’t see any money or weapons in the car. But on closer inspection officers found bundles of money hidden in cartons of washing powder. The older man and his girlfriend had already booked flights from Bucharest to Mykonos.