BP chief executive Tony Hayward and the company's advisor Mark Allen have also been asked to appear before the committee, according to officials who spoke only on the condition of anonymity because no announcement had yet been made.
Libyan-born al Megrahi was convicted of masterminding the 1988 bombing of Pan Am flight 103, which killed 270 people, most of them American. He was sentenced to life in prison but was released and allowed to return to Libya last year on compassionate grounds after it was determined he had only three months left to live. Al Megrahi beat the prognosis and lives on, now free in Libya.
In an interview with ABC News's Diane Sawyer and at a press conference alongside President Obama Tuesday, Prime Minister Cameron insisted repeatedly that the decision to release al Megrahi was solely that of the Scottish government and he has not seen anything to indicate that they were swayed by any lobbying efforts by BP. He also said he did not think there was a need for a U.K.-based inquiry into the matter.
"I don't need an inquiry to tell me what was a bad decision," he said. "It was a bad decision."
The British Prime Minister did say that while there was "absolutely not harm to be done" by providing a full explanation into the circumstances, he did not think there was "any great mystery here."
"There was a decision taken by the Scottish executive -- in my view, a wholly wrong and misguided decision, a bad decision, but their decision, nonetheless," he said. "That's what happened, and I don't think we need an extra inquiry to tell us that that's what happened."
Obama said he agreed that the release of al Megrahi was a "bad decision," but he said he fully supports efforts to learn more.
American senators from New York and New Jersey demanded a meeting with Cameron, and have scheduled public hearings on the al-Megrahi matter for next week. Cameron had initially declined to meet with the senators, but said he changed his mind Tuesday because he recognized "the strength of feelings" about the Lockerbie bomber, a Downing Street spokesman told ABC News.
"Our discussion with the prime minister was frank and serious," Schumer said after the meeting. "We urged the British government to pursue a complete and independent investigation, not simply a document review. The prime minister listened to our request and said that a full investigation was not off the table."