“The man lay dead on the street. There was a machine gun in the grass,” a witness who arrived on the scene shortly after the accident told the Aftonbladet newspaper.
Police commander Claes Ohlsson confirmed for Sveriges Television (SVT) that one of the robbers had died in the crash.
It was shortly after 10.30am when four men parked their black Jaguar outside the Guldfynd jewelry store in central Varberg.
Donning masks, three of the assailants darted inside carrying baseball bats and wooden clubs to rob the shop.
From the street, glass could be heard shattering inside the store, and the three men emerged again, racing back toward the Jaguar.
“No one was hurt,” Lars Grimbeck, a spokesperson for the Halland police, told the TT news agency.
The fourth member of the gang, who had been sitting outside in the waiting vehicle, stepped on the gas and the Jaguar peeled out of sight at high speed.
The quartet's getaway took them out onto route 153, which heads east toward Ullared and Värnamo, but their escape didn't last long.
After driving a little more than a kilometre, the driver lost control of the vehicle for as of yet unknown reasons, causing it to veer off the road and into a lamp post.
"One of the guys was tossed out and probably flew 15 to 20 metres before he landed on the other side of the road," witness Christoffer Svensson told the Expressen newspaper.
The man who was thrown from the car, along with two other men were injured so severely that they were unable to leave the area and were taken to hospital for treatment. The fourth man managed to flee on foot, but was later arrested.
One of the men taken to hospital later died from his injuries.
According to TT, the Jaguar used in the heist was stolen in Kungälv in western Sweden on Wednesday.