The UK claims sovereignty over the island, which forms part of the Chagos archipelago and has been home to an extensive US military facility since the early 1970s.

The BIOT Supreme Court agreed in May that a case concerning the status of 59 Tamil Sri Lankan asylum seekers, including 16 children, who allege that they have been unlawfully detained on the island since October 2021 after being rescued at sea.

In April, the court agreed to grant bail to the asylum seekers, meaning they can now leave their encampment and access the island’s beaches — but they have been denied access to virtually all of the civilian infrastructure on the island, which is run by the US military and includes shops, a post office, bars, night clubs and sport facilities.

Two days of hearings were set to take place this week, with a British judge, lawyers from UK firms Leigh Day and Duncan Lewis and BBC journalists intending to travel 6,000 miles to attend. This would also be the first time the asylum seekers would meet their lawyers face-to-face.

However, the US said last week that it is “withdrawing its consent” for the lawyers and journalists to attend on the basis of “security and operational concerns”, the BBC reports.

The US said plans to visit the encampment and other parts of Diego Garcia in the course of the court proceedings presented “risks to the security and effective operation” of its military base, for reasons which are “confidential and based on the US’s assessment of its own national security needs”.

The BIOT Supreme Court subsequently cancelled the court hearing.

Leigh Day solicitor Tom Short, representing a number of the claimants, said the cancellation was “a devastating blow to our vulnerable clients” and a hearing on Diego Garcia should be rescheduled as soon as possible.

The International Court of Justice (ICJ) has previously ruled that the UK’s administration of the Chagos Islands, which are also claimed by Mauritius, is unlawful.