‌Markwayne Mullin, the Republican senator from Oklahoma who led the delegation, said he hoped to find “common ground” with Ms Daniel-Selvaratnam but was “not able to find a path forward”.

‌“At this point, well-intentioned American citizens are facing a dozen years in prison all for unknowingly having one or two bullets in their luggage,” he said.

‌“The unintended consequences of [Turks and Caicos’s] law have been at the expense of well-intentioned American tourists, including a grandmother who had no intention of breaking the law.

‌“Should they receive a prison sentence, we will need to consider additional actions to safeguard American citizens.”

‌The delegation included one other senator, John Fetterman, three members of the US House of Representatives and an official from the US state department.

Interference of US politicians condemned

‌The UK Foreign Office, which is responsible for the islands’ foreign policy, declined to comment, citing ongoing legal action.

‌But Alicia Kearns, the chairman of the Foreign Affairs Committee, defended the prosecutions and condemned the interference of American politicians in the islands’ legal affairs.

“I think it’s pretty outrageous that US congressmen think it’s acceptable to fly to a British territory and essentially suggest that they disregard their own laws,” she told The Telegraph.

‌“I don’t think it is unrealistic to expect that when people fly, they should make sure they’re not carrying live ammunition.

“Quite frankly, this isn’t some small territory that congressmen can think they can intimidate and threaten. This is part of the British family.”

‌Sharlene Cartwright-Robinson, a former elected premier of Turks and Caicos and president of the Friends of the British Overseas Territory charity, said the islands’ judiciary should not be “weakened by interference or intimidation”.

‌“Turks and Caicos Islands should be admired for its strong system of governance and separation of powers which protects the legitimacy of the institutions,” she said.

‌“It is a sad situation that seems to be continuing when an easy fix would simply be for travellers to thoroughly check their bags.”