A group of four U.S. senators said a 123-page report on the release of Lockerbie bomber Abdelbaset al-Megrahi shows London worked on his release to preserve commercial interests in Libya.
"The families have suffered long enough and it's time to acknowledge the truth: justice was traded for commercial interests," said U.S. Sen. Frank Lautenberg, D-N.J., in a statement.
Megrahi was released in August 2009 on compassionate grounds following a terminal cancer diagnosis.
Sen. Robert Menendez, D-N.J, who led an inquiry last year into the Scottish decision to release Megrahi, said he felt there was a link to the decision and an oil deal between British energy company BP and the Libyan government.
A London inquiry into the case found there was no contact between BP and Scottish officials in the case. BP did lobby the British government but its involvement ended before Megrahi was sent back to Libya by Scottish authorities, The Daily Telegraph newspaper in London reports.
Sen. Chuck Schumer, D-N.Y., discounted many of the claims by the British government.
"The British government and BP wanted Megrahi released so that an oil deal being negotiated with Libya could go forward," he said in a statement.
U.S. interest in the case gained steam after the BP oil spill in the Gulf of Mexico in April.