Gasoline prices hit all-time highs in the District this week, shattering the previous record set July 16, 2008, according to the Automobile Association of America’s Mid-Atlantic office.

The price of regular gasoline has jumped 9 cents since Monday to $4.21 a gallon, 2 cents higher than the previous record.

The record comes even though the benchmark price of crude oil — the main component of gasoline prices — fell 15 percent last week and Thursday settled at $98.97 a barrel, two-thirds the level when the previous gasoline retail price record was set.

“This is not only unseemly, it’s also very painful,” said AAA spokesman John B. Townsend II.

On Wednesday, D.C. Attorney General Irvin B. Nathan said that his office is investigating the city’s largest owner of gas stations for potential antitrust violations. Capitol Petroleum, based in Springfield, owns about half of the gas stations in the District.

Only six states have higher gas prices than the District, where retail prices are 23 cents higher than the national average and 31 cents higher than in neighboring Virginia, AAA said.

In a letter to Nathan, Townsend called the price spike “unjustified.” Area gas station operators and distributors initially blamed the Mississippi River flooding and the fear of refinery disruptions for higher prices, Townsend said.

“Traders realized their fears of potential flood damage to the refineries along the Mississippi River were overblown. In fact, those refineries are continuing to operate normally,” he said. “Although the fears of damage to the refineries have eased, pump prices in the District have not, for the most part.”