The Nigerian president has denied rumours he died following a period of ill health and was replaced by a Sudanese clone.
Muhammadu Buhari addressed the speculation as he met members of the Nigerian community in Poland, where he is attending the UN COP24 climate summit.
"It's the real me, I assure you," he said, answering a question from the audience. "I will soon celebrate my 76th birthday and I will still go strong."
The repeated claims, spread on social media and in YouTube videos, alleged that the Nigerian leader was an impostor named "Jubril".
According to a statement issued by the president's spokesman Garba Shehu, President Buhari said: "A lot of people hoped that I died during my ill health.
"Some even reached out to the vice president to consider them to be his deputy because they assumed I was dead."
The leader branded those behind the rumours "irreligious" and "ignorant", but said later in a tweet that they were "not surprising".
It comes after Mr Buhari spent a large part of last year being treated for a serious illness in London.
The nature of his ill health has never been revealed to the public.
The lack of detail about the president's condition, his gaunt appearance and a reduction in public appearances have fuelled the rumours.
They emerged a month after Mr Buhari returned from another long medical trip to the UK.
Many of those endorsing the rumour were known critics of the Nigerian leader and his government.
© Sky News 2018