The state human rights watchdog on Monday advised police to make interpretation services available when questioning foreign nationals involved in a criminal case.

The National Human Rights Commission of Korea (NHRCK) advised the National Police Agency chief to improve the system and remove language barriers in order to protect the lawful rights of foreign nationals under investigation.

The recommendation came as a result of a petition by a South Korean woman to the commission that her Moroccan husband was investigated without interpreter services in March. The NHRCK said that it violated the man's legal rights under the Constitution.

The Moroccan was arrested on charges of assault for allegedly getting into a fight with a pedestrian while working.

He was immediately taken into custody and investigated without an interpreter present. The police said the man, who has been living in South Korea since 2012, seemed to have no trouble communicating in Korean.

The NHRCK said, however, the police should not assume the man could understand the local criminal justice process, just because he could have daily conversations in Korea. It also said the police should prevent a situation where foreign nationals "experience disadvantages or are discriminated against" because of language barriers.

The watchdog recommended that the police take disciplinary actions against the police officers involved in the case and educate them on the issue.

In line with the recommendations, the human rights watchdog also advised the police to prepare documents related to the criminal investigation process, including the Miranda warning, in multiple languages at local police stations.

The Moroccan man was acquitted of his assault charges by the prosecution in June. (Yonhap)