Kenya and Somalia on Monday argued their maritime boundary case before the International Court of Justice (ICJ) at the Hague.
Somalia sued Kenya in 2014 asking for a proper determination of the sea border between the neighbouring countries.
The bone of contention is rights of exploration and collection of revenues from lucrative oil reserves in an area estimated to be about 100,000 square kilometres in the Indian Ocean.
Kenya and Somalia had in 2009 reached a memorandum of Understanding (MoU) which was then deposited in the UN in 2011.
Kenya accuses Somalia of reneging on the MoU, but the man who signed that MoU for Somalia says the government’s hands were tied when Parliament rejected it.
The case will be heard over the next four days but reports indicate that the dispute could threated exploration rights that Kenya has granted to oil and gas companies already working in the area.