The Nigerian government says at least six Nigerian nationals are still waiting for asylum applications to be processed.
Thirteen Nigerians who fled the war in Ukraine have now been released from detention in Poland, the government has said.
The Nigerians in Diaspora Commission (NIDCOM) said on Wednesday that most people who had been detained at camps in Poland were now free.
"The Nigerians were released with the intervention of the Nigerian Ambassador to Poland," a statement read.
At least six others -- including a man who claimed he is Cameroonian -- were still waiting for their asylum applications to be processed, it added.
NIDCOM and the ambassador in Poland said they would continue to work and "ensure that the interests of Nigerians are well taken care of".
Before the Russian invasion, there were several thousand African students living in Ukraine.
Nigerian authorities say they acted "swiftly" to bring over 1,600 nationals back to the country, but others stayed and were later held in detention centres at the Ukrainian border with Poland.
African citizens have repeatedly accused security officials of racism amid evacuation efforts from Ukraine.