The government said a committee created to monitor price rises during the tournament would check if the actions by MATCH Services "can be characterised as cartel". It will analyse the hotel reservations made by MATCH in the 12 World Cup host cities to check if they affect market prices.
Government officials will also meet the airline industry next week to make sure there are no excessive increases in travel prices.
President Dilma Rousseff created the monitoring committee following projections of outrageous price rises during the World Cup.
A study by Brazil's tourism board earlier this year showed that some hotel rates would be up to 500% more expensive during the tournament in some hotels offered by the Fifa-appointed agency. According to Brazilian law, anything more than 20% of the local market can be considered cartel.