Nazi warship Karlsruhe which was sunk by a British submarine 80 years ago is discovered on the sea bed off the coast of Norway

A Nazi warship sank by the British has been found 80 years later, after a power company stumbled across it while inspecting their underwater lines.

The Karlsruhe was returning from the Nazi invasion of Norway in 1940 when it was torpedoed by HMS Truant, forcing the Germans to scuttle the sinking ship.

But while the story of the Karlsruhe is recorded fact, it's location remained a mystery – until now.

Norwegian power company, Statnett, found the vessel after identifying a wreck close to its underwater lines in the strait of Skagerrak.

Nazi warship, the Karlsruhe, was returning from the invasion of Norway in 1940 when it was hit by a torpedo from British submarine, the HMS Truant

For 80 years the location of the wreck remained a mystery - until now. It was found off the coast of Norway by a Norwegian power company, Statnett. Pictured: a scan of the wreck

'You can find Karlsruhe's fate in history books, but no one has known exactly where the ship sunk,' said Frode Kvalø of the Norwegian Maritime Museum.

'Moreover, it was the only large German warship that was lost during the attack on Norway with an unknown position.

'After all these years, we finally know where the graveyard of this important warship is.'

The existence of a wreck 13 nautical miles from Kristiansand in southern Norway was first revealed by sonar during a Statnett inspection in 2017.

But it wasn't until June this year that Statnett engineer, Ole Petter Hobberstad, was given the chance to inspect the ship, using a remote-controlled submarine.

The existence of a wreck 13 nautical miles from Kristiansand, a city in southern Norway, was first revealed by sonar in 2017, but in June this year an inspection of the ship was carried out that discovered it was the lost Nazi warship

Footage of the Karlsruhe, found 490 meters below sea level, shows the ship upright with cannons pointing into the sea

'When the ROV results showed us a ship that was torpedoed, we realized it was from the war,' said Mr Hobberstad.

'As the cannons became visible on the screen, we understood it was a huge warship. We were very excited and surprised that the wreck was so big.'

Footage of the wreck site reveals how it is adorned with a swastika, topped by a Nazi eagle or Parteiadler, with an anchor shape underneath.

The guns and barnacle-encrusted superstructure are visible too.

The first images also show that, unusually for a ship with a high centre of gravity, the Karlsruhe remained upright after sinking.

'Karlsruhe stands firmly 490 meters below sea level with cannons pointing menacingly into the sea,' said Kvalø.

'With the main battery of nine cannons in three triple turrets, this was the largest and most fearsome ship in the attack group against Kristiansand.'

'To find such a special war wreck is rare and extra fun for us who work with underwater investigations,' added Mr Hobberstad.

An inspection of the wreck by a remote-controlled submarine found the guns and barnacle-encrusted superstructure clearly visible

Statnett engineer, Ole Petter Hobberstad who inspected the ship said: 'We understood it was a huge warship. We were very excited and surprised that the wreck was so big.'

To find such a special war wreck is rare. The warship has nine cannons in three triple turrets, and was the largest and most fearsome ship in the attack group against Kristiansand

Despite its array of firepower, the Karlsruhe was only used as a troop transport for the attack on Kristiansand.

But coming under fire from Norwegian coastal guns at Odderøya Fortress, she soon joined the fight.

It was later that very same day, having successfully landed troops in Norway, that she was struck by two British torpedoes.

With her power soon disabled by the influx of water, the ship's pumps cut out and commander Friedrich Rieve made the decision to abandon ship.

One of her escorts, the torpedo boat, Greif, then rescued the crew and torpedoed the Karlsruhe twice more to ensure she sank.

Rieve was harshly censured for his actions, however, since he did not attempt to have the warship towed back to Kristiansand for repairs.

The HMS Truant would outlive its rival by six years, sinking en-route to a shipbreakers in December 1946, having been sold for scrap the previous year.