Updated

Attorney General Eric Holder says this week's drop in oil prices should put government investigators and regulators on alert for instances of fraud and manipulation that keep prices for consumers at the gasoline pump artificially high.

Holder issued his call Friday to be vigilant about "suspected illegal activity" to a government task force that recently was set up to investigate whether there are illicit forces behind the recent surge in gasoline and other energy prices.

The attorney general said in a memo that he realizes there will not be a perfect correlation between the decline in oil prices and the cost of a gallon of gasoline. But he said that if wholesale prices continue to decline, consumers also should pay less when they fill up.