On a visit to French Polynesia, France's interior minister said he would launch a review into whether companies were abusing their market dominance to jack up prices and contribute to the notoriously high cost of living in French overseas territories.

Interior Minister Gerald Darmanin announced that he would work with the Minister for Overseas Territories, Philippe Vigier, to "take stock" of abusive practices.

"There are too many economic monopolies in the overseas territories in general and in French Polynesia," Darmanin said in an interview with local television in the capital, Papeete.

He was speaking on Saturday, the final day of a three-day visit to the semi-autonomous country, during which he discussed the issue with its president, Moetai Brotherson.

"We're going to propose to President Brotherson that we tackle these monopolies together, because where there are monopolies, prices are very high and where prices are very high, it's everyday Polynesians who struggle to get by," Darmanin said.

Chronic problem

Prices in overseas territories have long outstripped those in mainland France, with successive governments pledging to do something about it.

The problem has worsened in the past decade, according to national statistics office Insee, which reported last month that consumer price differences had widened between 2015 and 2022.

An average household's shopping is now around 9 percent more expensive on Reunion Island than on the mainland and nearly 16 percent more expensive in Guadeloupe, Insee says.

The gap is even more pronounced when it comes to food, with prices as much as 39 percent higher in French Guiana, 40 percent higher in Martinique and 42 percent higher in Guadeloupe.

Telephone and internet services are also significantly more expensive across the board.

At the same time, the overseas territories have some of the highest unemployment rates and lowest average incomes of anywhere in France.

Parliamentary inquiry

The promise to investigate monopolies comes the month after a parliamentary inquiry called for drastic action to tackle runaway prices in France's overseas territories.

"When the patient is in cardiac arrest, it is no longer time for palliative measures," said Johnny Hajjar, MP for Martinique and the inquiry's rapporteur.

The proposals included incentives to boost local production and reduce dependence on imports, which make up around 60 percent of food products sold in the territories.

The parliamentary committee also recommended renegotiating yearly with large distributors to pressure them to cut back generous profit margins throughout the distribution chain.

It called for such groups to automatically report all their results to the competition watchdog, and demanded that mergers resulting in a single group holding more then 20 percent of market share be subjected to an inquiry investigating the impact on consumers.

As part of its hearings, the committee interviewed the head of Groupe Bernard Hayot, one of the largest food retailers in the French overseas territories with nearly 27 percent of the market in Reunion, 25 percent in Martinique and just under 20 percent in French Guiana.

Managing director Stephane Hayot denied having a monopoly or taking advantage of a lack of competition to inflate profit margins, and defended the group's policy of not publishing its financial statements.