Mauritius' opposition leader Navin Ramgoolam was appointed prime minister on Tuesday, returning to the post a decade on after his coalition won a near clean sweep of seats in parliament in a general election.

Ramgoolam's Alliance du Changement (ADC) coalition won a landslide 60 of the 62 national assembly seats, state broadcaster Mauritius Broadcasting Corporation reported.

The ADC earned 62.6% of votes in Sunday's ballot, the election commission said, prompting incumbent Prime Minister Pravind Jugnauth to resign.

Ramgoolam, 77, said that his first act in office would be to dismantle what he called the country's spying system "so that Mauritians will be free to talk".

He has served three previous terms as prime minister.

"We will also work to put an end to the rising cost of living for the population by better monitoring the value of the rupee, lifting Value Added Tax from basic commodities, and vanquishing nepotism, corruption and repression," Ramgoolam told reporters.

Despite steering the Indian Ocean archipelago to 7.0% economic growth last year, Jugnauth's popularity appeared to have been badly dented by a cost of living crisis and corruption allegations.

Jugnauth conceded on Monday, saying he tried to do what he could for the country's 1.3-million people, but that his Alliance Lepep coalition was heading for a huge defeat.

Last month Jugnauth, who has been in office since 2017, negotiated an agreement for Britain to cede the Chagos Islands while retaining the US-UK Diego Garcia air base.

Jugnauth's Alliance Lepep won 27.8% of the vote, according to a tally of results released by the Office of the Electoral Commissioner (OEC).

The Organisation du Peuple de Rodrigues won the island of Rodrigues' two seats, with 50.0% of the vote there, the OEC said.

Earlier this month, Jugnauth's government blocked social media platforms until a day after the election, citing national security concerns after conversations between public figures were leaked. It lifted the ban a day later.