Attorney General Eric Holder will appoint a task force to examine both gasoline sales and potential manipulation in oil markets.
"Based upon our work and research to date, it is evident that there are regional differences in gasoline prices, as well as differences in the statutory and other legal tools at the government's disposal," Holder said in a memo accompanying a statement announcing the task force.
Neither the president nor Holder have offered any evidence of actual fraud, and both admit there are legal, logical reasons for the rising price of gas. But Obama says he wants to make sure that no one uses the current market as an opportunity for criminal activity.
"We're going to make sure that no one is taking advantage of American consumers for their own short-term gains," Obama said.
There's not much Obama can do to affect the price of gasoline in short term, something he acknowledged in his remarks. Gas prices have risen steadily as a result of tensions in the Middle East and northern Africa and rising demand from China and other emerging economies.
The current average price of gas is about a dollar higher than this time last year. Locally, it's up about a quarter from last month.
In L.A. and Long Beach, a gallon of regular is averaging $4.22. In Orange County and the Inland Empire, it's $4.20, and in Ventura, the average price is $4.22.
The Associated Press contributed to this story.