Eight Democratic senators asked the Justice Department on Wednesday to investigate whether any of the chief executives of five major oil companies lied or misled Congress during a recent hearing on industry profits.

The issue involves a question by Sen. Frank Lautenberg, D-N.J., at the Nov. 9 hearing about whether any of the oil companies' representatives participated in Vice President Dick Cheney's 2001 energy task force activities.

Testifying at the Senate hearing were the chief executives of Exxon Mobil Corp., Chevron Corp., ConocoPhillips, Shell Oil Co., and BP America Inc.

Four of the executives said they were not aware of any such participation; a fifth said he did not know.

In subsequent letters, seeking to clarify their responses, the executives reiterated that they believe they responded truthfully. Some also acknowledged that their companies had contacts with task force staff members and discussed energy priorities.

"Many of these latter statements (by the oil executives) admitted participation in task force activities and raised greater concern about the accuracy of the hearing testimony," the senators wrote Attorney General Alberto Gonzales.

While the executives were not under oath, the testimony may have violated federal laws prohibiting false statements to Congress, the letter said.

The Justice Department had no comment on the Democrats' letter and noted that Lautenberg had made a similar request on Nov. 16.

Assistant Attorney General William Moschella responded to that request by asking the senator to provide specific examples of alleged violations of law.

The hearing was held by both the Senate Commerce, Science and Transportation Committee and the Senate Energy and Natural Resources Committee.

Bill Wicker, a spokesman for Sen. Jeff Bingaman of New Mexico, the top Democrat on the Energy Committee, said Bingaman and other committee Democrats have concluded that neither Lautenberg's question, nor the executives' response was "sufficiently precise ... to convince us that they delivered answers untruthfully."

"We felt we didn't have enough hard evidences that any of the witnesses ... intentionally didn't tell the truth," Wicker said Wednesday. "But whether there are grounds for the Justice Department to take action is something the Justice Department is going to have to decide."

Three of the senators who signed the letter to Gonzales — Sens. Maria Cantwell of Washington, Daniel Inouye of Hawaii and Ron Wyden of Oregon — are on the Energy Committee.

The others are Senate Democratic leader Harry Reid of Nevada and Sens. Dick Durbin of Illinois, Barbara Boxer of California and Edward Kennedy of Massachusetts.

Cheney's task force issued its report outlining the administration's energy priorities in May 2001. Cheney's office has steadfastly refused to disclose what private parties may have participated in the process.