UNITED NATIONS — The top UN envoy for North Korea, Maurice Strong, decided to suspend his work while investigators probe his ties to a South Korean businessman accused of wrongdoing in the UN oil-for-food scandal, a UN spokesman said Wednesday.

Secretary General Kofi Annan is also reconsidering a policy that Strong and other part-time UN employees like him are not required to disclose their finances to avoid possible conflicts of interest, said associate spokesman Stephane Dujarric.

Strong, a prominent Canadian businessman, is the UN point man on stalled six-country talks aimed at persuading North Korea to abandon its nuclear weapons programs. He denies any involvement with the $64 billion US oil-for-food program in Iraq and has pledged to co-operate with a probe into the program led by former U.S. Federal Reserve Chairman Paul Volcker.

But his admitted ties with Tongsun Park, a native of North Korea and citizen of South Korea, are raising questions about a possible conflict of interest with his UN role. Strong acknowledged on Monday that Park invested in an energy company he was associated with in 1997.

On Tuesday, Annan said he had not known about Strong's ties to Park, who was also accused in the 1970s of trying to buy influence in Congress.

Park was thrust into the spotlight last Thursday, when the U.S. Attorney's Office accused him of accepting millions of dollars from the Iraqi government while he allegedly operated in the United States as an unregistered agent for Baghdad, lobbying for oil-for-food.

Dujarric said Wednesday that Strong informed the secretary general "that he will defer any further action on his Korean assignment until the question of his association with Tongsun Park is clarified and resolved, which he hopes will be done expeditiously. "

"The secretary general agrees that this is the appropriate thing to do,'' Dujarric said.

Mark Malloch Brown, the secretary general's chief of staff, said Strong was suspending himself even though the U.S. Attorney's office has not contacted him and he faces no charges.

"Given the controversy, I think he's doing absolutely the right thing and we welcome it,'' Malloch Brown said in an interview with two journalists.

Strong also informed the United Nations that Volcker's committee is investigating whether he had any ties to the oil-for-food program, Dujarric said.

The United Nations itself is also studying whether it was appropriate for Strong to have ties with Park given Strong's role as envoy to the region.

Park was known to have been close to former UN secretary general Boutros Boutros-Ghali, according to current and former UN staff.

Spokesmen for Volcker's Independent Inquiry Committee would not comment on whether they had already interviewed Strong in connection with oil-for-food, but in a statement the committee said his "readiness to co-operate'' was welcomed.

The oil-for-food program, which ran from 1996 to 2003, was created to help Iraqis cope with UN sanctions imposed after Saddam Hussein's 1990 invasion of Kuwait. It let the Iraqi government sell limited -- and eventually unlimited -- amounts of oil primarily to buy humanitarian goods.

But Saddam chose the buyers of Iraqi oil and the sellers of humanitarian goods. In a bid to end the sanctions, Saddam allegedly gave former government officials, activists, journalists and UN officials vouchers for oil to be resold at a profit.

The criminal complaint could be damaging to the United Nations because it mentions that Park had met several times with two unidentified UN officials in apparent efforts to gain their support on oil-for-food.

The U.S. complaint calls for the arrest of Park, who was reported to be hiding in Tokyo and considering a U.S. plea bargain offer, according to South Korea's JoongAng Ilbo daily.