The existence of Oyo’s son was first publicly revealed in the days after the king’s death by President Museveni, who said he had been told about the young boy by the queen mother.
No other details have officially been disclosed, and he had not previously been presented as Oyo’s heir.
The disagreement has exposed the complicated way in which succession works in Tooro.
Unlike Britain’s monarchy, where the crown passes according to an established line of succession, Tooro’s monarch is chosen from the Babiito, the royal dynastic clan.
At a press conference in the kingdom’s capital of Fort Portal, the royal clan’s succession committee announced Kijanangoma, Oyo’s cousin and a news presenter at the state-run broadcaster UBC, as monarch.
The clan elders said they had the customary authority to choose a suitable prince to become “the Omukama” – the local title for the king of Tooro.
The succession panel said it had carried out “due diligence, consultation and adequate consideration” before selecting Kijanangoma, with 19 members signing the resolution.
Kijanangoma is the son of Prince Christopher Paul Kijanangoma and a grandson of former Tooro king George David Rukidi III.
Another royal, UK-based Prince George Desmond Kamurasi, was initially considered for the throne but declined, citing other responsibilities, according to the succession committee.
It is not yet clear when the enthronement will take place, but the committee said it would be conducted in accordance with the traditions and customs of the Tooro kingdom.
