North Korea should let farms produce freely and allow food to be sold in local markets because the communist government cannot provide enough food for its people, a U.N. human rights investigator urged Monday.

Vitit Muntarbhorn said North Korea's regime stopped small-scale farming and closed local markets last year as part of a long-term clampdown on the agricultural sector. Thieving from the military is also hurting the income of farmers and contributing to hunger, he said.

The government took these drastic measures "because it wanted people to revert back to the public distribution system — to be dependent upon the state," Muntarbhorn told reporters.

The U.N. estimates that 8.7 million people need food aid in North Korea. The country has relied on foreign assistance to feed much of its population since the mid-1990s when its economy was hit by natural disasters and the loss of the regime's Soviet benefactor.

North Korea, ruled by Kim Jong Il, is routinely described in U.N. and other reports as one of the world's most repressive regimes.

Despite the tight controls, Muntarbhorn, a Thai professor, said some North Korean farmers are continuing to eke out a meager living by selling their goods directly to citizens. He even noted rare protests among women in the country.

Muntarbhorn has never been allowed to visit North Korea, which views his mandate as a violation of its sovereignty.

Basing his information on U.N. and non-governmental agencies active in North Korea, he said soldiers routinely steal or extort agricultural produce from farmers in the country. He said interviews with refugees also provided valuable information about the plight of rural North Koreans.

"People should be able to generate that food and keep it rather than being extorted as they are today," Muntarbhorn said. "They should be able to trade — to generate income the state is not able to provide."

Muntarbhorn presented his report Monday at the U.N. Human Rights Council, prompting an angry North Korean rebuttal.

North Korean diplomat Myong Nam Choe accused the investigator of being part of a Western effort to discredit the Pyongyang government.

Muntarbhorn also criticized North Korea's currency revaluation last year for drastically cutting people's assets.

North Koreans must trade 100 "won" for 1 unit of new currency of the same name, as part of a government effort to remove money from the economy and root out elements of capitalism, he alleged.

"This was a push to curb the market system," Muntarbhorn said, "and control the circulation of money in the process."