PETALING JAYA: Deported North Korean chemist Ri Jong-chol is demanding an apology and compensation from Malaysia after claiming to have suffered "painful police questioning" while in custody, says a report.

Ri told Japan's international broadcasting service NHK World in Beijing on Sunday that the Malaysian Government and police had forced him to confess and caused him pain.

During the interview, Ri sang a song praising North Korea and said that he had the song in mind when enduring the "painful questioning" by Malaysian police.

The 47-year-old denied any involvement in the death of Kim Jong-nam and claimed that he had no knowledge of the killing when he was detained.

Ri's demand for an apology and compensation comes after he accused Malaysian police of threatening to harm his family unless he confessed to the killing.

This was rubbished on Sunday by Inspector-General of Police Tan Sri Khalid Abu Bakar on Sunday, who labelled the claims as nonsense.

Khalid said that the authorities followed strict standard operating procedure in the murder investigation and that Ri was "treated well".

Ri also told NHK World that he lived next to the North Korean embassy's second secretary and that they were on greeting terms.

Malaysian police are currently looking for the embassy's second secretary.

However, Ri said that he had no knowledge of his whereabouts.

Commenting on Malaysia's expulsion of North Korean ambassador Kang Chol, Ri claimed that the move is only an extension of "Malaysia's plot against him."

When asked why he had not worked at the Malaysian company that hired him, he told NHK World that the company's business was not the kind of work he wanted to do.

Instead, Ri said that he exports soap materials to North Korea.

Malaysian authorities insisted that Jong-nam – the half brother of North Korea’s leader Kim Jong-un – was killed by the VX nerve agent, which was smeared on his face by two female assassins at Kuala Lumpur International Airport 2 on Feb 13.

However, North Korea and its ambassador Kang have persisted with allegations that Malaysia was “colluding” with others in the murder.

A high-level delegation, which arrived from Pyongyang, also rejected an autopsy finding that its citizen “Kim Chol” – the name that Jong-nam travelled by – was poisoned and had instead died of a heart ailment without giving any proof.

Police had detained Ri on Feb 17, but released and deported him on March 3 due to a lack of evidence. He has since been blacklisted from entering Malaysia.