Swedish police said Thursday they have arrested a person suspected of stealing priceless royal jewels from a cathedral in broad daylight in July.

In the daring heist, thieves in a motorboat made off with two gold burial crowns dating from 1611 and an orb that had been locked in a glass cabinet in Strangnas Cathedral, around 100 kilometers (60 miles) from Stockholm.

The crowns, which had belonged to King Karl IX and his wife Queen Christina, are made of gold, pearls and precious stones.

"None of the stolen goods have been found and we are continuing the investigation with interrogations, among others," the police said in a statement.

Prosecutors have until Saturday to decide whether the suspect, who has not been identified, should be remanded in custody.

The theft occurred in July, and police quickly had helicopters, patrols, and search dogs looking for the thieves, who risk up to six years in prison for aggravated theft.

(Cover: The royal jewels, dating from the 17th century, belonged to King Karl IX and his wife Queen Christina. /AFP Photo)