Cameroon's opposition leader Issa Tchiroma Bakary, who has declared himself the winner of the 12 October elections, has told the BBC that he will not accept a stolen vote, with the results due to be announced on Monday.

He says his team has compiled the overall picture based on results from individual polling stations, so there is no doubt.

Tchiroma Bakary, 76, is a former government minister who broke ranks with President Paul Biya, 92, who is seeking another term after 43 years in power.

The ruling party has dismissed Tchiroma Bakary's victory claims and several officials have described it as illegal because only the Constitutional Council can proclaim official results.

In an interview at his home, in the northern city of Garoua, Tchiroma Bakary said he had urged his supporters to defend their votes.

We will never accept their votes being stolen by anyone, he said, dressed in a long, flowing white and gold tunic.

The former minister said he was not concerned about being arrested or put in jail, but I know that I have already won the presidential election.

There is no doubt, no shadow of doubt whatsoever. My victory is undeniable, he said, appearing placid and resolute throughout the conversation.

Tchiroma Bakary has previously said he won the election with about 55% of the vote, based on returns representing 80% of the electorate.

Asked whether he would accept defeat if someone else is declared the winner, he said he would agree provided the Constitutional Council announces the results that comes from the ballot box, not ballot stuffing.

Tensions over the delayed announcement of the election results have been growing, sparking fears of post-electoral violence in a country already rocked by a separatist conflict in the Anglophone regions and Boko Haram insurgency in the Far North region.

Despite his recent role as the government's mouthpiece, Tchiroma Bakary drew huge crowds at his rallies, electrifying voters desperate for change. After four decades of Biya's rule, economic development has stagnated and challenges such as inflation, unemployment and insecurity abound.

In Garoua, a general feeling of uncertainty lingers following protests earlier this week. Security forces patrol the streets during the night, although their presence in the day time has decreased.

The highly respected and influential Catholic Church in Cameroon this week urged calm following fears that violence could erupt once official results are declared.

Born in Garoua, Tchiroma Bakary trained as an engineer in France, but his political career took flight after spending six years in prison for alleged political dissent against President Biya. Now, he stands as a potential beacon of hope for many Cameroonians yearning for change.