The gang rammed the van from behind as it drove down the slip road of the M271 in Hampshire, minutes after staff at the firm's regional headquarters near Southampton had loaded it with the cash for a special delivery.
The robbers lay in wait in a six-ton truck and followed the van as it pulled on to the northbound slip road from the Nursling industrial estate at about 6.15am, police said. The gang used traffic cones and a blue arrow to trick the security van over to the near side.
The truck smashed into the back of the van then pulled in front and forced it to stop on the hard shoulder. The driver and his two colleagues were forced to drive four miles to a country lane near Romsey, where they were told they would be shot unless they opened the locked van.
They were bundled into the back where they were bound, gagged and handcuffed. A large tarpaulin was then pulled over the van and the guards watched as the raiders helped themselves to hundreds of cash bags, which they put into a white truck later found abandoned on the A27.
Inspector Derek Stephens said: 'This was obviously a very carefully planned raid. It was professionally executed. They've vanished off the face of the earth.' The guards, who needed treatment for shock, eventually struggled free and raised the alarm. Motorway roadblocks were set up. Later, 36 empty cash bags were found beside the A272 near Billingshurst, 45 miles away.Reuse content