The ship Skytterens was sunk by its own captain because it did not want the precious cargo to fall into the hands of the Nazis during World War II.

Since then, the wreck, which can hold up to 400,000 liters of oil, has deteriorated.

The Swedish Maritime Administration has classified Skytteren as the biggest environmental threat among the environmentally hazardous wrecks in Sweden.

Especially because the wreck is so degraded after lying on the seabed for almost 80 years.

The work is complicated and dangerous.

Eight divers take turns working on the ship for one hour at a time.

You drill into the spaces where the oil is and then pump it up to the ship on the surface.

But the work became more complicated than first thought.

The oil has in some places in Skytteren changed consistency and become like heavy thick oil.

To be able to pump the oil, you have first had to heat it with steam.

So far, around 60,000 liters of oil have been pumped from the wreck, but the work is weather-sensitive and has dragged on.

It is hoped that the Sagittarius will now be emptied within four weeks.