VIENNA (Reuters) - A truck full of refugees discovered abandoned on an Austrian motorway on Thursday contains more than 70 bodies, the interior ministry said on Friday, announcing an updated death toll.

Austrian police had originally put the toll at up to 50 and are due to announce the exact number within hours. The vehicle had come to Austria from Hungary.

The refrigerated truck was found by an Austrian motorway patrol near the Hungarian border just before lunchtime on Thursday, with fluids from the decomposing bodies seeping from its back door.

It had been left abandoned on the roadside of the highway, which leads from Hungary to the Austrian capital Vienna.

"Work continued throughout the night, but I expect all the bodies have been removed now," said Helmut Marban, a police spokesman for the Burgenland province. "Forensic investigators are still at the lorry and trying to establish all the facts."

The truck is at a customs building in the village of Nickelsdorf, which has refrigeration facilities and where forensic specialists clad in white protective suits and yellow rubber boots could be seen wheeling body bags away.