Lockerbie bomber and former Libyan intelligence officer Abdelbaset al-Megrahi was released from prison by Scottish officials in August 2009 on compassionate grounds because of a terminal prostate cancer diagnosis.
Following the oil spill in the Gulf of Mexico last year, U.S. lawmakers started examining whether Megrahi's release was tied to a BP deal to look for oil in Libya. British, Scottish and BP officials deny charges Megrahi's release was related to oil.
U.S. Sen. Robert Menendez, D-N.J., who led an inquiry last year into Megrahi, said he felt there was a solid case linking Megrahi's release to oil.
U.S. Sen. Kirsten Gillibrand, D-N.Y., in a statement last week, said with the rebel-backed Transitional National Council gaining momentum, it was time to bring the Lockerbie bomber to justice.
The Scottish government said there was contact with Megrahi's family and stated that his medical condition is consistent with someone suffering from terminal prostate cancer.
"Any change in Megrahi's circumstances would be a matter for discussion with the National Transitional Council as the legitimate governing authority in Libya," the Scotish government said in a statement.
Megrahi is the only person convicted for the 1988 bombing of Pan Am Flight 103 in which 270 people died.