The unification ministry on Friday rejected as "fake news" allegations that the two North Korean fishermen deported from South Korea last month were brokers helping North Koreans fleeing the communist nation.

The two fishermen in their 20s were sent back to the North last month, five days after they were captured near the eastern inter-Korean sea border. After an inter-agency investigation, the South Korean government concluded that they killed the captain of their boat and 15 fellow crew members.

Earlier this week, a North Korean defector running an online news outlet in South Korea claimed, citing unidentified North Korean sources, that the deported fishermen were actually trying to help the 16 other crew members to defect. 

"The claim that the two North Korean fishermen were brokers who had no relations to the killings is just fake news that is not based on any facts," deputy ministry spokesperson Kim Eun-han told a regular press briefing.

The official also expressed "strong regret" over the circulation of groundless allegations and said the government will review "corresponding legal actions" against distribution of "inaccurate information."

The deportation of the North Koreans marked the first case since the 1950-53 Korean War.

The two North Koreans expressed a desire to defect, but the government concluded their intentions were insincere, saying that they appeared to be trying to flee from the North Korean authorities after committing a serious crime.

Critics have accused the government of hastily repatriating them based only on their confessions, and said that they should have been allowed to exercise their right to a fair trial or to challenge the government's probe results.

In a joint letter to President Moon Jae-in earlier this week, Human Rights Watch and 66 other non-governmental organizations expressed concerns over the government decision to deport the North Koreans despite its obligation "to protect anyone who would be at substantial risk of torture or other serious human rights violations after repatriation."

South Korea has maintained that it has handled the case according to due principles and standards when little evidence other than their confessions was available.

The government also stressed that it considered the safety of South Korean citizens as one of the top priorities, though vowing to seek legal and regulatory measures to supplement the existing manuals to batter cope with similar cases in the future.

There are around 32,000 North Korean defectors living in South Korea.

Seoul usually accepts North Koreans as defectors if they wish to resettle here to avoid oppression and poverty and it repatriates those who drift to the South in a fishing vessel, according to their wishes. (Yonhap)