David Cameron has called on Commonwealth countries to toughen up their approach to the Maldives over the "unacceptable" actions of its government.
The Prime Minister said members of the 53-nation group, which includes the the Indian Ocean island state, must send a strong and consistent message to the country about the need for reform and the release of political prisoners.
It follows the ousting last year of the country's first democratically-elected president, Mohamed Nasheed, who was later jailed.
At the Commonwealth Heads of Government Meeting (Chogm) in Malta, Mr Cameron said the group must push for action on human rights issues.
He said: "It must do more to hold countries to account when they fail to live up to their responsibilities as Commonwealth members.
"That's why I urged all members to send a strong and consistent message to the Maldives on the need for political dialogue and the release of political prisoners. What's been going on there is unacceptable."
Mr Cameron also urged the Commonwealth to step up action to wipe out corruption, warning it fuels terrorism and wrecks economies.
The Prime Minister brought together 10 countries for a meeting at the summit in a fresh push to tackle the problem.
"It corrodes our societies, it can even ferment terrorism as people give up hope in good and honest government," he said.
The UK will hold the next Commonwealth summit, which is being held in spring 2018.