The U.N. office on North Korea's human rights is intensifying its investigation into Pyongyang's dismal rights record ahead of the first anniversary of its establishment, government officials said Friday.

The United Nations opened its field office on June 23 last year in Seoul in a bid to monitor North Korea's human rights violations, recommended by the U.N. Commission of Inquiry (COI)'s landmark report on the North's rights record.

Signe Poulsen, representative of the office, and her colleagues, have been conducting interviews with North Korean defectors at a resettlement center since February.

The Seoul office is conducting written interviews with defectors at Hanawon, a facility where defectors receive a three-month resettlement education after coming to South Korea, according to Seoul's unification ministry.

If required, the office is carrying out in-depth face-to-face interviews to further glean evidence of North Korea's widespread violations of human rights.

North Korea has long been labeled one of the worst human rights violators in the world. Pyongyang has bristled at such criticism, calling it a U.S.-led attempt to topple its regime.

The communist regime does not tolerate dissent, holds hundreds of thousands of people in political prison camps and keeps tight control over outside information.

The COI report accused North Korea of committing "systematic, widespread and grave violations of human rights."

In December, the U.N. General Assembly adopted a resolution for the second consecutive year that calls for referring the North to the International Criminal Court (ICC) for human rights violations.

In March, the U.N. Human Rights Council set up a group of independent experts which will seek ways to punish North Korean human rights violators.

"The establishment of the group is aimed at finding ways to bring North Korean rights perpetrators to the ICC," said a ministry official.

A new law aimed at improving the North's dismal treatment of its people was passed in March after years of being held up in parliament due to political wrangling between conservatives and liberals.

In accordance with the law, Seoul is seeking to establish a center tasked with investigating the North's human rights violations and creating a relevant archive. (Yonhap)