The retail price of beef is at its highest level since the first case of mad cow disease in the United States was discovered in December 2003, the farm ministry said Monday.

The nationwide average retail price for 100 grams of chilled loin domestic beef had gained 6 yen as of last Friday to 706 yen compared with the previous week, the Agriculture, Forestry and Fisheries Ministry said.

The price had been hovering around 700 yen since hitting 706 yen in early June due to a ban on U.S. beef imports. The renewed high was prompted by a jump in demand for beef for barbecuing during the Bon holiday season, a ministry official said.