The new variant of the coronavirus comes after a second was reported in South Africa - where cases are soaring along with its continental neighbour.
While all viruses undergo multiple mutations, as many as two a month, most mutations don't change the virus's behaviour - or its power.
However the UK and South African variants do, it is believed, making the virus more transmissible - speeding up the rate at which it spreads among humans.
Britain and South Africa's new variants of the SARS-CoV-2 do appear to be more contagious and have led to new travel restrictions and turmoil in markets.
Now in Nigeria, the head of Africa's disease control body has revealed another new variant of the novel coronavirus seems to have emerged and says more investigation is needed.
"It's a separate lineage from the UK and the South African lineages," John Nkengasong, director of the Africa Centres for Disease Control and Prevention (CDC) told an online news conference from Addis Ababa.
The news comes as cases are surging in both Nigeria and South Africa.
In the past week, Nigeria reported a 52 per cent increase in cases and South Africa a 40 per cent increase, Nkengasong said.
He said there was no evidence the new variant was contributing to increased transmission in Nigeria, but cautioned the country does less genomic surveillance than Britain.
The Nigeria CDC and the African Centre of Excellence for Genomics of Infectious Diseases in Nigeria will study more samples, Nkengasong said.
"Give us some time ... it's still very early", he said, in response to questions about the variant.
Nigeria's principal Covid-19 investigator has just released publicly the genomic sequences of the new variant, he added.
Nigeria's CDC did not immediately respond to a request for comment on Nkengasong's remarks when approached by Reuters.
"Over recent weeks, we've had a huge increase in number of samples to (the Nigerian CDC's) reference lab," the Nigeria CDC's director general Chikwe Ihekweazu tweeted on Thursday.
"This has led to an unusual delay with testing, but we're working round the clock."
Nigeria, Africa's most populous country with more than 200 million people, has seen fewer coronavirus cases than many others on the continent.
Total cases crept past 80,000 on Wednesday.
Daily recorded cases exceeded 1,000 for the first time this month.
Africa has reported more than 2.5 million coronavirus cases, making up 3.3% of global cases, according to the Africa CDC.
The new, faster-spreading variant that South Africa detected on December 18 is now the predominant one there, Nkengasong said, although - as with the new variant in Britain - there is no evidence that it leads to a more severe disease.
The rate of coronavirus infections in South Africa will soon surpass the peak hit in the first wave earlier in the year, its health ministry said on Wednesday.
Nkengasong said the Africa CDC did not believe the mutation in South Africa will affect deployment of the Covid-19 vaccines on the continent.