(CNN)A precious gold coin that's in the Guinness Book of Records for its unsurpassed purity was stolen early Monday from a museum in Germany.
200-lb gold coin worth estimated $4 million is stolen from German museum
The coin, which weighs more than 200 pounds and has a diameter of more than 20 inches, was taken from the Bode Museum in Berlin after 2 a.m. local time. German media reports put the current value of the gold coin at 3.7 million euros, or slightly more than $4 million.
Nicknamed "the "Big Maple Leaf," the coin was issued by the Royal Canadian Mint in 2007, ahead of Queen Elizabeth II's state visit to Germany. It has a face value of more than $1 million and a purity of 999.99/1000 gold.
The coin had been in the Bode Museum collection since 2010.
After the theft, Berlin police say a ladder was found near railway tracks close to the museum. They are investigating if it was used in the burglary.
The coin has a portrait of Queen Elizabeth II on one side and a maple leaf on the other.