India on Wednesday supported Mauritius’ claim to the disputed Chagos islands during proceedings at the International Court of Justice, PTI reported.

The Chagos archipelago is one of the 14 British Overseas Territories. The United Kingdom took possession of the islands after capturing them from Mauritius in 1810. Mauritius eventually gained independence in 1968. But, in 1965, the Chagos islands were “detached” from the colony of Mauritius and the largest island – Diego Garcia – was then leased for 50 years to the United States to be used as a military base.

Mauritius disputes the United Kingdom’s rights over the islands and there have been several questions over whether its rulers were under duress in 1965 while signing the agreement, especially since independence was just three years away, according to The Wire.

India’s Ambassador to the Netherlands Venu Rajamony on Wednesday told the International Court of Justice that according to “historical facts”, Mauritius always had sovereignty over the Chagos archipelago. Rajamony was representing India at a four-day hearing that is being held on the United Nations General Assembly’s request. The hearings began on Monday.

“The process of decolonisation of Mauritius remains incomplete both technically and in substance as long as the Chagos archipelago continues to be under UK’s colonial,” Rajamony said. “The understanding reached in November 1965 between Mauritius and the United Kingdom for the retention of Chagos by the United Kingdom for defence purposes and return thereof to Mauritius when no longer needed for defence purposes, is also in itself evidence that Mauritius has been and continues to be the sovereign nation for the Chagos archipelago.”