COLOMBO - The Maldives has put former president Mohamed Nasheed back in jail a month after his 13-year prison sentence was commuted to house arrest, sparking clashes between his supporters and police in the honeymoon island nation.

Nasheed's Maldivian Democratic Party (MDP) said police and prison officials clashed with its supporters as they removed him from his home in the capital Male and took him to the high-security prison island of Maafushi on Sunday night. "Nasheed's transfer back to jail is in clear breach of the Maldives' constitution, which provides no provision for reversing a commutation of a sentence," the MDP said in a statement Monday.

Human rights lawyer Amal Clooney, who is representing the former president, said the move showed "complete disregard for the rule of law". "After subjecting Nasheed to an unfair trial and outrageous conviction, this capricious administration has now reversed its decision on house arrest," the MDP quoted her as saying.

"They have the audacity to claim that there was no commutation of Nasheed's sentence even though we have official documents and public statements confirming the opposite." There was no immediate comment from the government.

The MDP said it had filed a complaint Monday with the criminal court challenging his transfer from house arrest.

Nasheed, the archipelago's first democratically-elected leader, was sentenced to 13 years in jail in March after a court convicted him under tough anti-terror laws.

The charges relate to the arrest of a judge accused of corruption when Nasheed, who was toppled in February 2012, was president.

Supporters of the former leader maintain his conviction was a politically motivated attempt to silence him, and his legal team has already petitioned the United Nations over his conviction.

Nasheed's sentence was formally commuted to house arrest on July 19 and it is not clear why he was taken back to prison.

He had earlier been moved to the main island of Male to receive medical treatment under an apparent deal with the Maldives government after closed-door talks with the opposition MDP aimed at ending political unrest.

Authorities had also said they would appeal against Nasheed's conviction for terrorism, which sparked mass protests on the islands and drew international criticism.

The MDP has since called on President Abdulla Yameen to honour commitments made in the talks to release high-profile political prisoners including Nasheed and to quash criminal charges against some 1,700 dissidents.

The party said it had honoured its side of the bargain by providing parliamentary support for the sacking of Yameen's vice president Mohamed Jameel on treason charges, among other matters.

It also supported a controversial legal change that would allow foreign ownership of land for the first time in the Indian Ocean archipelago.

US Secretary of State John Kerry warned in May that democracy in the Maldives was under threat, saying Nasheed had been "imprisoned without due process".

Nasheed's lawyers resigned before the end of his trial, saying it was aimed at destroying his career, and the United Nations termed his jailing "vastly unfair".

It came at a time of growing opposition to the government of Yameen, who beat Nasheed in a run-off presidential election in late 2013.

Nasheed, a climate change activist who was also imprisoned during the three-decade rule of former strongman Maumoon Abdul Gayoom, was elected president in 2008.

He then rose to international prominence by hosting a cabinet meeting underwater to draw attention to the dangers facing the islands' existence from global warming and rising sea levels.

His jailing and the subsequent unrest have tarnished the image of the Maldives as an upmarket tourist destination.

Amnesty International said earlier this year that protesters in the Maldives were being frequently beaten up while the media faced a growing number of death threats.