Mohamed Nasheed, the first democratically elected leader of the Maldives, was sentenced to 13 years in prison after being found guilty of terrorism in March.
A senior UN human rights official who visited him urged government to take action on his flawed trial, news agency Reuters reported.
Nasheed, a respected human rights and environment campaigner, was elected president in the Maldives' first free polls after the end of 30-year autocratic rule of Maumoon Abdul Gayoom in 2008.
In February police dragged Mohammed Nasheed into court despite his protests that he would go willingly on his own.
Countries including India and the US expressed concern about Nasheed's treatment and trial.
India and Maldives relationship was flourished during his regime. Both the countries collaborated closely on a range of issues to bring peace and security to the region.
A large number of Indian population resides in Maldives. Indians are the second largest expatriate community in the Maldives with approximate strength of around 26,000. Indian expatriate community consists of workers as well as professionals like doctors, teachers, accountants, managers, engineers, nurses and technicians etc.