As gas prices reached an all-time nationwide high Monday, Sen. Charles Schumer called for a federal investigation into refinery maintenance problems.

Oil companies claim unexpected refinery problems and repairs are causing the increase in prices. However, Schumer believes the companies themselves are to blame. He said they're deliberately not keeping up on maintenance in order to inflate prices.

Dowling College economist Marty Cantor agrees with Schumer's allegation. "The only sensible conclusion could be that they're manipulating production to increase the price, because the supply is there," Cantor said.

With the current mood in Washington, an anti-trust investigation into oil companies is possible, Cantor said.

A gallon of gasoline on Long Island costs an average of $3.19, 26 cents higher than last month. Related Information:GasBuddy.com Gas Prices by State U.S. National Gas Temperature GasPriceWatch.com U.S. Department of Energy AAA Fuel Gauge Weekly U.S. Retail Gasoline Prices