History buff Gunnar Rosenlund enlisted the help of independent research group SINTEF to aid in his search for King Magnus VI's long lost sarcophagus.

Using georadar, the researchers said they were 90 to 95 percent certain that the church’s 900-year-old walls contained metal objects of some kind.

In their report, the researchers said: "Although one cannot be sure what's inside the wall, the measurements are consistent with a sarcophagus containing the metal from, for example, a suit of armour."

Rosenlund believes the mystery find lends credence to his theory that Magnus VI's heavily decorated royal coffin has been hidden for centuries in the thick cathedral walls.

”They have found the sarcophagus of Magnus the Law-mender. It can’t be anything else,” he told broadcaster NRK.

As the cathedral is a listed building, Rosenlund must now await the opinion of the Directorate for Cultural Heritage before deciding how to proceed.

With the directorate’s permission, he hopes researchers will be able to drill a hole in the wall to see what lies within.

”It’s a miracle that this coffin has survived all this time. The church has burned down three or four times, along with the town, and has been subjected to numerous pirate raids,” said Rosenlund.

Born in 1238, Magnus VI ruled as king of Norway from 1263 to 1280. Known also as Magnus the Law-mender for his efforts to improve the legal code,  the regent died in Bergen after a short illness in 1280.

Although Magnus VI is known to have been buried at Bergen Cathedral, his tomb has never been found.     

But not everybody shares Rosenlund’s conviction that the tomb is now close to being uncovered.

Øystein Ekroll, an archaeologist and royal expert, said the practice of burying royals in the walls of churches remained common a century earlier but had lost its appeal by the time of Magnus VI’s death.

“There could be a lot of things inside the wall, but I don’t believe it’s a king’s grave,” he told NRK.

According to Ekroll, the king’s tomb likely disappeared during one the many renovations carried out on the church over the centuries.