The US embassy in Nigeria has released a statement condemning what it describes as "recent misleading posts on social media" linking the current global outbreak of monkeypox to "so-called 'US-controlled laboratories' in Nigeria".
It says such reports are "pure fabrication" with "zero merits" and says there are no US-controlled labs in Nigeria.
On 27 May, Russia asked the World Heath Organization (WHO) to investigate what it said were US-funded Nigerian labs in Abuja, Zaria and Lagos in light of the global spread of monkeypox.
Monkeypox was first detected in humans in 1970 in Africa and since then most cases have been reported in rural and rainforest areas in the region.
Of late it has spread to western countries in Europe, North America and beyond.