The South Korean president’s office has declared that nearly 2 tonnes of prized pine mushrooms that were a gift from Kim Jong-un, the North Korean leader, are safe to consume after an opposition politician warned the mushrooms could be contaminated with radioactive fallout from the North’s nuclear tests.

The mushrooms were sent to Moon Jae-in, the South Korean president, after the two leaders’ summit in Pyongyang in September. Mr Moon, in turn, said he would donate the gift to 4,000 people who have not been able to see their relatives in the North since the end of the three-year Korean War in 1953.

With a thick white stem and a brown cap, the mushrooms are considered a delicacy and there were reports ahead of the summit that officials in Pyongyang had ordered residents of North Hamgyong Province to scour hillsides for the finest examples of the fungus.

Quoting sources inside North Korea, the DailyNK web site reported that the authorities were exchanging 22 lbs of flour (worth £5.70 - a considerable sum inside one of the poorest countries on Earth) for 2.2 lbs of mushrooms. The authorities were also bartering sugar and rubber boots for mushrooms.

As well as being famous for its annual crop of pine mushrooms, North Hamgyong is also the site of the Musudan-ri rocket launch facility and the regime’s Punggye-ri nuclear proving grounds.