Ri Jong-Chol was the only North Korean detained in connection with the murder of the estranged half-brother of Pyongyang's leader. Malaysia released and deported him two days after it charged two women with the killing.
A North Korean suspect questioned in connection with the murder of Kim Jong-nam, the estranged half-brother of North Korea's leader, has called the Malaysian investigation a "conspiracy" to dishonour North Korea.
He also accused the Malaysian police of trying to coerce a confession out of him.
Ri Jong-Chol, who was one of the suspects detained, spoke to reporters outside the North Korean embassy in Beijing on Saturday after Malaysia released him citing insufficient evidence. Kim was killed on February 13 at Kuala Lumpur International Airport. South Korea and Malaysia have both accused North Korea of being involved in the murder.
The investigation was "a conspiracy to impair the dignity of the Republic [North Korea]," the 47-year-old said, accusing Malaysia of using coercion to try to extract a confession from him.
Ri denied any involvement in the murder. He said the police had presented him with "fabricated evidence," and said he would be rewarded with a comfortable life in Malaysia if he confessed.
He said he was not at the airport on the day of the killing, and knew nothing about the accusation that his car was used in the case.
Ri was the only North Korean detained over the attack and was deported two days after two women — one Vietnamese and one Indonesian — were charged with murdering Kim.
Malaysian police believe the two women smeared Kim's face with VX nerve agent, a chemical classified by the UN as a weapon of mass destruction.
CCTV footage shows two women approaching the 45-year-old and apparently smearing his face with a cloth. Police say he suffered a seizure and died less than 20 minutes later.
South Korean intelligence and US officials say the murder was an assassination by North Korean agents.
Kim, who had been living in the Chinese territory of Macau under Beijing's protection, had spoken out publicly against his family's dynastic control of isolated, nuclear-armed North Korea.
Malaysia denies violating UN sanctions on North Korea
Malaysia has rejected any suggestion it may have violated UN sanctions on North Korea, after a report which said Pyongyang-linked firms were running an arms network in the country.
Malaysia has for years been one of the few countries in the world to have strong ties with North Korea, but their relationship has been damaged by the killing of Kim.
"Malaysia categorically rejects any such insinuation," said the foreign ministry in a statement on Saturday.
The report said North Korean intelligence agents used a front company called Glocom to run an arms operation out of Malaysia.