The police chief has said he believes they fled to Pyongyang while the other three are hiding in North Korea's embassy in Kuala Lumpur.
He was holding a diplomatic passport in the name of Kim Chol when he was killed.
North Korea says the recent "incident" involving the death of leader Kim Jong-Un's half-brother was a plot by South Korea and the USA to bring the regime down.
Last week, Malaysia formally identified the murder victim as Kim Jong-nam.
Since 2008, photographer Eric Lafforgue ventured to North Korea six times.
Deputy national police Chief Noor Rashid Ibrahim said: "I was made to understand that they are leaving it to our government to deal with it (the body). yes, they have given their consent".
But as relations soured, Malaysia recalled its envoy from Pyongyang and expelled the North Korean ambassador.
Indonesia sentences Brit, Aussie to prison in cop's death
A British man was today convicted of killing an Indonesian traffic police officer in Bali and sentenced to six years in prison. Australian national Sara Connor , right, reacts during her verdict trial in Bali, Indonesia, Monday, March 13, 2017.
Together they executed more than 10 pranks and Siti was paid US$100-US$150 each time depending on her performance.
"We judge that the move reflects the USA parliament's serious concerns over North Korea's threats and its bipartisan, tough stance on the need for an in-depth review of the issue to put the North back on the list of state sponsors of terrorism", a senior official at Seoul's Ministry of Foreign Affairs said, declining to be named.
They are seeking help from Interpol member countries that include China to arrest and extradite them to Malaysia to face murder charges.
He said that now "in response to North Korean nuclear missile "experiments", the United States and its allies take steps to bolster exercises and other military activity, which in turn pushes Pyongyang to new provocative actions", AFP reported. "We do not know what their demands are - we need to figure out what we can do to get the best result", he told reporters.
Four of the seven North Korean suspects being sought by Malaysia are believed to have left the country on the day Kim was killed.
Although Malaysia has never directly accused North Korea of being behind the attack, many speculate that it must have orchestrated it.
South Korea's spy agency has said it believes North Korea was responsible for the assassination of Mr Kim, who had spoken out against his family's dynastic control of the nuclear-armed north.