Indian Ocean islanders who were moved to make way for the US military base at Diego Garcia have won a historic High Court battle with the British Government to return to their homeland.

Lord Justice Laws and Mr Justice Gibbs ruled there had been "an abject legal failure" and overturned a 1971 ruling that banned the Chagos islanders, or Ilois, from returning to their land.

Louis Bancoult, 37, chairman of the Chagos Refugee Group in Mauritius, brought the court action claiming he and hundreds of others were exiled and impoverished when they were removed to make way for the base.

Richard Gifford, a lawyer for the islanders, said the government would now have to come up with a lawful policy in the light of the judges' findings.

Following the ruling, the judges began discussions with lawyers about how it will be implemented.

Britain rented the island, which is halfway between Africa and southeast Asia and is part of the British Indian Ocean Territory, to the USA for use as a military base. In 1971 the UK barred anyone from entering the islands except by permit.

The islanders argued that as British subjects, they had the right to return home.

The Foreign Office has said Britain had arranged for Ilois community members to visit the island and assess the current condition.

"We are taking the advice of consultants to assess whether people could return to the outer islands and what the environmental impact would be. Their work is not complete and we are asking them to continue it," according to an FCO statement in July.

The entire population of the Chagos archipelago - 2,000 people according to the islanders, but only 1,000 according to the British government - was relocated between 1967 and 1973. A few were sent to the Seychelles, but most were shipped to Mauritius - both island nations off Africa's east coast.