Sales of red ginseng products more than doubled in late April from a year ago as Chinese shoppers went on a buying spree of the medicinal plant at duty free shops and department stores, the ginseng agency said Friday. Korea Ginseng Corp. said sales of its red ginseng products, including its flagship brand Junggwanjang, rose more than 60 percent to 13.7 billion won (US$13.3 million) from April 25-29 compared with 8.3 billion won the same period of last year.