WASHINGTON (MCT) — The United Nations Development Program office in Pyongyang, North Korea, sits in a Soviet-style compound. Like clockwork, a North Korean official wearing a standard-issue dark windbreaker and slacks would come to the door each business day.

He would take a manila envelope stuffed with cash — a healthy portion of the United Nation's disbursements for aid projects in the country — and leave without ever providing receipts.

According to sources at the United Nations, this went on for years, resulting in the transfer of up to $150 million in hard foreign currency to the Kim Jong Il government at a time when the United States was trying to keep the North Korean government from receiving hard currency as part of its sanctions against the Kim regime.

"At the end, we were being used completely as an ATM machine for the regime," said one U.N. official with extensive knowledge of the program. "We were completely a cash cow, the only cash cow in town. The money was going to the regime whenever they wanted it."

Last week, the development program, known as UNDP, quietly suspended operations in North Korea, saying it could not operate under guidelines imposed by its executive board in January that prohibited payments in hard currency and forbade the employment of local workers handpicked by the North Korean government.

But some diplomats suspect the timing of the suspension was heavily influenced by a looming audit that could have proved embarrassing to the United Nations.

Documents obtained by the Chicago Tribune indicate that as early as last May, top UNDP officials at headquarters in New York were informed in writing of significant problems relating to the agency's use of hard foreign currency in North Korea and that such use violated U.N. regulations that local expenses be paid in local currency. No action was taken for months.

Then, under pressure from the United States, U.N. Secretary-General Ban Ki Moon on Jan. 19 ordered an audit of all U.N. operations in North Korea to be completed within 90 days, or by mid-April.

The Board of Auditors, the U.N. body tasked with the audit, made no movement on the audit for 40 days after Ban's order. It sent out its notification letter for the beginning of the audit on the same day the development program announced the closure of its office — March 1.

That timing, combined with past concerns about the UNDP's transparency, has raised suspicions that suspending operations would be a way to hamstring the audit, the results of which may prove damning to the organization.