The regime has apparently worked swiftly to close Camp 22 amidst claims that the warden of the camp and another officer had recently left North Korea for China. Camp 22 was in Hoiryeong which is in North Hamkyung Province. The camp was a Completely Controlled Zone. At its peak, it apparently held between 20,000 and 50,000 prisoners.
Although the camp was closed, it has been reported that no prisoners were released, but they were distributed to other prison camps. The camp initially started moving prisoners out in March this year and was fully closed by the beginning of June. It has been speculated that the camp was closed over fears that the two defectors would shed light on the human rights abuses in the camp.
Source: Daily NK.