More than a hundred advocacy and community groups have called on the US Government to close a migrant processing facility at the infamous US Navy base at Guantanamo Bay, in Cuba, and stop detaining asylum seekers found at sea there.

Legal aid and advocacy group the International Refugee Assistance Project has led groups in writing a letter to the White House calling for the closure of the detention centre.

 “The US government cannot continue to hide its diversion and mistreatment of asylum seekers by exiling them to Guantánamo, out of reach of their families, advocates, public consciousness – and the law,” the letter, sent to President Joe Biden, said.

Among the letter’s signatories is the Haitian Bridge Alliance, which advocates for Haitian migrants across the United States. The letter’s other 125 authors include immigration and human-rights groups, legal service providers, child advocacy groups and religious organisations.

Guantanamo Bay is known for holding suspected terrorists after the 9/11 attacks. But for decades, it has also hosted a separate facility for migrants, including thousands of Haitians and people who were HIV-positive at the turn of the 21st century.

Today, the US Government uses it to process people the US Coast Guard encounters at sea, including Cubans and Haitians asking for asylum.

Last month, an International Refugee Assistance Project report accused the US government of detaining refugees in inhumane, prison-like conditions at its Migrant Operations Centre – which the government denied.

“The United States has a long and notorious history of detaining people at Guantanamo without adequate legal protection or oversight, and the detention of asylum seekers and refugees there is part of this horrific history that is continuing today,” said project spokesperson Hannah Flamm.

The report said migrants at the centre, including families and children, were being held indefinitely and in prison-like conditions that violated their rights.

The group interviewed former staffers and immigrants who were processed at the centre as part of its investigation, which found migrants were receiving inadequate healthcare, little to no legal representation and were deprived of freedom of movement.

The US State Department rejected the report’s findings.

Meanwhile, a court in the US has ruled the government violated the rights of thousands of asylum seekers by refusing to allow them to enter the United States to pursue claims that they would be persecuted if returned to their home country

The 9th US Circuit Court of Appeals in San Francisco also rejected the government’s requirement that those who had travelled through another country must seek asylum there before applying for refuge in the US.

The restrictions before the court were adopted in the final months of President Barack Obama’s administration, enforced under President Donald Trump and largely rescinded by President Joe Biden.

But the Biden administration replaced those rules in June with a virtually absolute ban on asylum for people seeking to enter the US at the Mexico border.

That ban is being challenged in a separate lawsuit, before a federal judge in San Diego.

But if Donald Trump wins next month’s presidential election, he could seek to revive the rules that the court rejected, perhaps going to the right-wing leaning US. Supreme Court.

The policy, known as “metering,” prevented migrants from applying for asylum when the designated ports of entry at the border were full.

That forced them to wait in Mexico for months or even years, subjecting them, the court said, to hunger, homelessness and sometimes deadly criminal attacks.

Advocates for the asylum seekers argued that they were eligible to apply because they had reached the US. border before being stopped by federal agents.

Federal law says those who have “arrived” in the US can seek asylum. A majority of the appeals court judges said those who are stopped at the border have arrived, for legal purposes.