MEXICO CITY - Some of Mexico's most notorious drug capos irked by a price hike on junk food inside federal prisons found an ally in the country's consumer protection agency Wednesday.

The federal prosecutor for the consumer said prisoners shouldn't be gouged and should be able to buy products at the same price as the regular market.

The newspaper Reforma reported Wednesday that some of Mexico's most notorious drug bosses, including former Juarez cartel boss Vicente Carrillo Fuentes, were among dozens of signatories of a complaint to the consumer agency.

The agency announced later in the day that it had opened an investigation.

The prisoners complained that prices have jumped 20 per cent since prison commissaries were reorganized in October, boosting the price of a bag of Cheetos from $2.35 to $3.30.