The North Korean man being held by Malaysia in connection with the death of Kim Jong-nam is to be released and deported on Friday.
Malaysia’s Attorney General Mohamed Apandi Ali said Ri Jong Chol was “a free man” as there was “insufficient evidence to charge him”.
The estranged half-brother of North Korea’s leader died on 13 February – he was poisoned with VX nerve agent.
Two women were charged with his murder on Wednesday.
Malaysia is seeking to question several North Koreans, including an embassy official, suspected of being involved in the murder.
Also on Thursday, Malaysia announced it was ending visa-free travel for North Koreans, citing security reasons.
North Koreans can currently visit Malaysia for up to 30 days without securing a visa, under a reciprocal deal.
But Deputy Prime Minister Ahmad Zahid Hamidi has said that is changing as of Monday 6 March, the Bernama state news agency reports.
The two women, Doan Thi Huong from Vietnam and Siti Aisyah from Indonesia are accused of smearing the nerve agent on Mr Kim’s face while he was preparing to fly out of the budget airport in Malaysia’s capital, Kuala Lumpur.
Ri Jong Chol, who has lived in Malaysia for the last three years, was arrested four days later. Police did not provide details on why he had been detained.
On Thursday, officials said Ri Jong Chol will be deported because he does not have valid travel documents.
Reuters news agency reported that Mr Ri held a work permit that was valid till 6 February, 2017.
Diplomatic ties between North Korea and Malaysia were initiated in the 1970s, and as trade in resources such as palm oil and steel increased, North Korea eventually established an embassy in Kuala Lumpur in 2003.
But Mr Kim’s death has converted this relationship into a full-blown diplomatic rift, with Malaysia even recalling its ambassador from Pyongyang.