Hor Namhong will make the trip before an Asian security forum in July hosted by the Association of Southeast Asian Nations, ASEAN Secretary-General Surin Pitsuwan said.

Cambodia holds ASEAN's rotating leadership and has close ties with Pyongyang, Surin told reporters at the end of the grouping's annual summit in Phnom Penh.

"There is a special relationship between Cambodia and North Korea that was useful to ASEAN in the year 2000... and that was to bring North Korea into ASEAN Regional Forum," he said.

"I hope that Cambodia can play that unique role again and I understand the foreign minister is preparing himself to visit before the ASEAN ministerial meeting and ASEAN Regional Forum in July."

The forum is an annual gathering of foreign ministers from 27 countries, including ASEAN's 10 members as well as the US, China and Japan to discuss strategic security issues like the tense situation on the Korean Peninsula.

The two Koreas are members of the forum, making it an ideal venue for mediation outside of the so-called Six Party Talks.

Chosun Ilbo newspaper, citing a Seoul diplomatic source, said they arrived in the South Sunday after China changed its policy of refusing to let them depart.

Yonhap news agency and other media carried similar reports, and said China was also considering allowing the departure of seven others trapped for at least two years in South Korea's consulates in Shenyang and Shanghai.

China arrests and repatriates fugitives from North Korea, considering them to be economic migrants rather than potential refugees.

South Korea and international rights groups have urged it to change the policy, saying returnees can face harsh punishment.

The five who were allowed to leave Beijing include a daughter of a former South Korean soldier who was taken prisoner during the 1950-53 war and her two children, including a 17-year-old boy, Dong-A Ilbo newspaper said.

They had spent almost three years in the Beijing mission.

Seoul's foreign ministry declined to comment.

Chinese President Hu Jintao agreed to tackle the thorny issue of North Korean fugitives during a summit with the South's leader Lee Myung-Bak last week.

Tens of thousands of North Koreans have fled poverty or repression in their impoverished homeland, almost all of them across the border to China.

Some hide out among -- or marry into -- the ethnic Korean community in China's Northeast. Others try to travel on to Southeast Asian nations before flying to Seoul.

The rare decision by China to allow the refugees' departure is an apparent sign of its irritation at North Korea for a rocket launch planned this month, Chosun Ilbo said.

Pyongyang announced a plan to launch a satellite-carrying rocket to mark the centenary of the birth of its late founding president Kim Il-Sung, drawing international condemnation.

The North insists the launch is a peaceful space project. The United States and several other nations see it as a disguised missile test banned under UN resolutions.