DISCOVERY: Hidden paradise secretive tropical island surrounded by crystal blue waters

Diego Garcia, a remote island in the Indian Ocean, is a paradise of lush vegetation and white-sand beaches, surrounded by crystal blue waters.

But this is no tourist destination. It is strictly out of bounds to most civilians – the site of a highly secretive UK-US military base shrouded for decades in rumour and mystery.

The island, which is administered from London, is at the centre of a long-running territorial dispute between the UK and Mauritius, and negotiations have ramped up in recent weeks.

The BBC gained unprecedented access to the island earlier this month.

“It’s the enemy,” a private security officer jokes as I return to my room one night on Diego Garcia, my name highlighted in yellow on a list he is holding.

For months, the BBC had fought for access to the island – the largest of the Chagos Archipelago.

We wanted to cover a historic court case being held over the treatment of Sri Lankan Tamils, the first people ever to file asylum claims on the island, who have been stranded there for three years. Complex legal battles have been waged over their fate and a judgement will soon determine if they have been unlawfully detained.

Up until this point, we could only cover the story remotely.

Diego Garcia, which is about 1,000 miles (1,600 km) from the nearest landmass, features on lists of the world’s most remote islands. There are no commercial flights and getting there by sea is no easier – permits for boats are only granted for the archipelago’s outer islands and to allow safe passage through the Indian Ocean.

To enter the island you need a permit, only granted to people with connections to the military facility or the British authority that runs the territory. Journalists have historically been barred.

UK government lawyers brought a legal challenge to try to block the BBC from attending the hearing, and even when permission was granted following a ruling by the territory’s Supreme Court, the US later objected, saying it would not provide food, transport or accommodation to all those attempting to reach the island for the case – including the judge and barristers.