Copenhagen Letter/Brendan Killeen: It is being called the largest theft of cultural artefacts in Danish history. According to Erland Kolding Nielsen, director general of the Royal Danish Library, 3,200 valuable documents, pamphlets books and maps went missing from the Royal Library in Copenhagen between 1968 and 1978.
For 25 years the authorities had no idea what happened to the haul that included first editions from authors Thomas Moore and John Milton, philosopher Immanuel Kant, astronomers Tycho Brahe and Johannes Kepler and several hundred original prints by the reformer Martin Luther.
Also missing are a large number of maps by Willem Janszoon Blaeuw the leading Dutch cartographer of the 17th century.
However, at the end of last November, the library was tipped off by Christies, the London auction house, that several of its "precious works" were being offered for sale.
Attempts made to remove tell tale identification codes on the documents had apparently failed allowing the British authorities to trace the documents back to Copenhagen.
The story broke before Christmas but despite a lot of media attention reporting restrictions imposed by the courts mean exact details are still sketchy.
What is not disputed is the scale of the theft. The total sum of the missing items has been put at between €20 million and €27 million, if one can price such rare artefacts.
According to Helle Just Christiansen, the Copenhagen city prosecutor who will be representing the library, Danish police began an investigation in co-operation with their British, American and German counterparts after the tip-off in November.
This led them to an "ordinary house" in the Copenhagen suburbs, where 1,591 of the missing items were found. Four people are in custody including a 68-year-old widow, her son, his wife and an Irishman who has lived in Denmark for many years. The elderly woman's late husband was apparently employed in the library's oriental section.
"We believe that 80 items were sold between 1997 and 1998 through Christies in London and Swanns auctioneers in the United States for over 10½ million Danish kroner [€1.34 million]. Several of the documents sold for between three and five million kroner each," Christiansen said.
The library, which dates from 1673, recently had a breathtaking black granite extension added which dominates the surrounding skyline and has resulted in the building being christened the "Black Diamond".
This is not the first time the "Black Diamond" has been hit by thefts. In the autumn of 1999 Melvin Nelson Perry, a petty thief from Britain appeared in the library's map room wearing dark glasses, carrying a newspaper under his arm and requested to see a number of priceless atlases.
The fact that he spelt "cartographer" wrong when he signed the guest book, had dark, obviously dyed hair and spoke with a "vulgar accent" aroused the suspicions of the library attendant who apparently scared the would be thief off.
Fifteen months later, on January 29th, 2001, however, the "well-spoken" Peter Bellwood, an ex-landscape gardener from Leeds arrived at the library and over the next three days managed to remove eight maps including five from a rare 16th century Dutch travel book, the Itinerario.
Closed circuit video showed Bellwood using a razor to cut the maps from their bindings before hiding them under his loose fitting woolly jumper.
Library staff believe he had some sort of special vest in which he smuggled the maps out. Earlier this week, I took a look around the "Black Diamond".
It is a magnificent building with a sloping jet black facade which leans out over one of the entrances to Copenhagen's port. Apparently, there are more tourists and architecture students than scholars among its guests, a fact that makes security tricky.
However, the library doesn't appear to be helping itself in that regard.
Prominently displayed in the English section of the library bookshop is a book entitled: The Island of Lost Maps, A true Story of Cartographic Crime by Miles Harvey. Chapter five is entitled "How to take a map".
"It takes no time and you need only one tool. An out of the way spot is preferable but not necessary: with enough skill you can do this right in the middle of a busy rare books room," it reads before describing in detail how a small razor can be used to dislodge the map which can then be hidden under your clothes - the exact technique that Bellwood used. I decided to buy it. The woman behind the counter told me it was a great read.
I asked her if she also sold woolly jumpers. She said no, but they do have nice T-shirts.
The defendants in the latest "Black Diamond" case, including the mysterious Irish connection, will appear in court on Monday for a preliminary hearing.
The prosecutor's office will be pushing for their continued detention until the trial begins as Denmark has no bail system: defendants are either detained or released without conditions.
Apparently, people who have access to a lot of maps as well as disposable income pose an unacceptable risk.
The trail is set to run for four days in May.