Newspaper reports said on Thursday that the energy secretary, Jorge Seguro Sanches, had sent a letter to European Competition Commissioners Margrethe Vestager, asking Brussels to investigate the situation.
In his letter, Jorge Seguro Sanches stresses that the systematic deviations of the fuel prices practiced in Portugal compared with international prices are of concern to the government.
He said that over the last years there had been a series of price hikes that were not seen on the international market, with extremely negative repercussions for the domestic economy and consumers.
Jorge Seguro Sanches acknowledged that there had been many explanations, namely that at times the oil companies could have been colluding with each other, which may have infringed legal provisions.