The group is seeking an independent state for the south-east and adjoining areas.
Kayode Ogundamisi, a journalist, shared a video of the embassy on Facebook.
In the video, Uchenna Asiegbu, IPOB directorate head, is seen taking a guest on a tour of the facility.
Nnamdi Kanu, leader of the group and director of Radio Biafra, is facing charges of treason, and he has been in detention since 2015.
Kanu, who is regarded as the president of the “Republic of Biafra”, initiated the idea of planting “embassies” across the world.
The late Odimegwu Ojukwu, a retired army officer and revered Igbo leader, declared the old eastern region–comprising the south-east and the south-south – the Republic of Biafra in May 1967 after a massacre of the Igbo in the north.
But Ojukwu’s declaration was not entirely because of the massacre.
The Nigeria government under Yakubu Gowon, a retired general, thereafter, declared war on the new republic, which fell in January 1970 when Biafran forces surrendered.