WASHINGTON — Just as BP stopped oil from flowing into the Gulf of Mexico, the company faces unwelcome attention from the US Congress on another issue: whether it sought the release of convicted Lockerbie bomber Abdel Baset al-Megrahi to help get a $900 million exploration agreement with Libya off the ground.Soon after his release last year, BP acknowledged that it urged the British government to sign a prisoner transfer agreement with Libya, but stressed it did not specify al-Megrahi's case. It reiterated that stance this week when four US Democratic senators asked the State Department to investigate whether there was a quid pro quo for the Lockerbie bomber's release.Al-Megrahi served eight years of a life sentence for the Dec. 21, 1988, bombing of the Pan Am Flight 103 over Lockerbie, Scotland, killing 270 people, most of them American. Last August, Scotland's government released him on compassionate grounds and he returned to Libya.Secretary of State Hillary Rodham Clinton discussed the matter Friday with British Foreign Secretary William Hague and informed him of congressional interest in the circumstances regarding al-Megrahi's release and a possible BP connection.In a 12-minute phone call, Clinton told Hague that "it might be appropriate for the British government to communicate with Congress as well to make sure that they fully understand what transpired a year ago," State Department spokesman P.J. Crowley told reporters. He added that Clinton had not made any specific requests for information from the British but might do so in the future, and that the State Department had not yet determined how or if it could meet the request to investigate.