The leader of the unrecognised Federal Republic of Ambazonia (English speaking side of Cameroon), Sisiku Ayuk Tabe, alongside nine others, has been sentenced to life imprisonment by a military court in Yaoundé.
The leaders were declared guilty of "rebellion, complicity in terrorism, financing of terrorism, revolution, insurrection, hostility against the state, propagation of fake news and lack of identification."
The verdict was handed down on Tuesday morning.
Mr Ayuk Tabe and 46 other separatists had sought refuge in Nigeria, but were detained in Abuja by the Nigerian government in January 2018 and later deported to Cameroon.
According to the BBC, the defence team said: "There were irregularities in the proceedings, including the judge's biases, but the military court rejected his evidence."
The court also ordered the 10 to pay 1.250 billion FCFA to Cameroon as damages and 2.125 billion FCFA to the Civil Party.
The Nigerian Incident
PREMIUM TIMES last year reported how Nigerian authorities arrested leaders of the group who are leading the separatist movement in Cameroon.
At least seven leaders of the 'Movement for the independence of Southern Cameroonians' were arrested by the State Security Service on a Friday in Abuja.
The group were leading a movement for an independent Ambazonia State, which seeks to break away from the domination of French-speaking Cameroon.
Cameroon witnessed months of unrest as the push for the independent state intensified, resulting in clashes between protesters and the police.
Dozens of people were killed, including members of the security forces.
Anglophone Cameroonians say they have been marginalised for years by the central government and the country's majority French-speaking population.
The agitation for secession heightened in October 2017 when the "Ambazonians" declared an autonomy over their region during the anniversary of their union with the French-speaking side.
The declaration was however rejected by the Paul Biya government resulting in violent clashes.
In December, a delegation from Mr Biya was received by Nigeria's Vice President, Yemi Osinbajo.
The government said at the time that the purpose of Mr Osinbajo's meeting with the Cameroonian delegation, led by the country's minister of Territorial Administration and Decentralisation, Rene Sadi, was to strengthen diplomatic ties between the two nations.
A source, however, said the meeting was also meant to broker a secret agreement for Nigeria's security officials to help arrest about 15 people declared wanted by the Cameroonian government.
The United Nations Refugee Agency says at least 7,500 refugees from Cameroon's English-speaking population have since fled to Nigeria since the crisis erupted.
Southern Cameroon comprising its English-speaking population joined their French counterpart in 1961, a year after the country's independence from colonial rule.