North Korea has sold fishing rights in the East Sea to China, in addition to the ones it sold in the Yellow Sea, to raise funds for its leaders, government sources familiar with the matter said Thursday.

The North earns about 82 billion won ($75 million) annually from the sale of the fishing rights to its biggest ally in its coastal waters. All earnings have been funneled to prop up Kim Jong-un's leadership, according to the sources.

"It has been confirmed that Pyongyang has rolled up its sleeves to earn foreign currency by selling the fishing rights in its waters to China. Our analysis shows it has sold the rights above the Northern Limit Line (NLL) in the East Sea," an intelligence source said.

It is widely known that the North has sold fishing rights to China in its waters above the NLL in the Yellow Sea, but this is the first confirmation that the communist state has sold fishing licenses in the East Sea.

"North Korea is selling fishing licenses through an intermediary trade agency," the source said. "But it looks like North Korea plans to manage fishing rights sales directly in the future."

In 2004, Pyongyang and Beijing signed a deal to allow Chinese vessels to catch fish in the East Sea well above the NLL, but the allowed fishing areas didn't include the waters near the inter-Korean sea demarcation line, a government source said.

He pointed out that given 900-1,000 Chinese vessels have recently been spotted fishing near the northern side of the sea demarcation line, it is confirmed that China has bought more fishing areas from the North.

The sources said some 2,500 Chinese fishing boats are estimated to be fishing in the East Sea and the Yellow Sea waters. 

North Korea's earnings from fishing right sales are more than double what the National Intelligence Service reported to the National Assembly's Intelligence Committee last month. The NIS then said North Korea sold $30 million worth of fishing rights in the Yellow Sea to more than 1,500 Chinese vessels. (Yonhap)