Simon Ekpa was jailed last year after a Finnish court found he was a key figure in groups advocating independence for Biafra, in southeastern Nigeria.
A Finnish court on Thursday cut from six to four years a prison sentence handed to a Nigerian separatist leader convicted of "terrorism" for promoting independence for the Biafra.
Last year, the Paijat-Home district court found Simon Ekpa, a 41-year-old dual Finnish-Nigerian national, guilty of participating in the activities of a "terrorist" group and inciting others to commit crimes for "terrorist" purposes.
The court found he was a key figure in groups advocating independence for Biafra, in southeastern Nigeria, where a 1967-1970 civil war left hundreds of thousands dead.
The Court of Appeal upheld the lower court's ruling, finding him guilty of "terrorism" offences, committed in part on social media, while he was living in the Finnish city of Lahti between 2021 and 2024.
But it reduced his prison sentence by two years due to "the circumstances" surrounding his actions in the Biafra.