US: Megrahi should return to prison
The Obama administration has said that the Lockerbie bomber, returned to Libya a year ago, should be sent back to a Scottish jail.
The president's office said it had advised Libyan officials of its view that Abdelbaset Ali Mohmed Al Megrahi should not be free.
Speaking on the first anniversary of the bomber's release from Greenock prison on compassionate grounds, US President Barack Obama's counter-terrorism adviser John Brennan criticised the "unfortunate and inappropriate and wrong decision". He said: "We've expressed our strong conviction that Al Megrahi should serve out the remainder - the entirety - of his sentence in a Scottish prison."
New Jersey senator Robert Menendez said that a "cloud of suspicion" hung over the decision to release Megrahi, who has terminal prostate cancer.
The bomber returned to jubilant scenes in Libya on August 20 last year where he remains alive - despite being given three months to live at the time.
Mr Menendez and three other senators have written to Scottish First Minister Alex Salmond and Prime Minister David Cameron laying out the areas where "questions linger". The information requested in the correspondence relates to Megrahi's medical diagnosis and communications between BP and the British Government.
US politicians want to investigate concerns that the bomber's release was linked to an oil deal - a suggestion that has been strongly denied by all parties involved.
Speaking at a news conference in New Jersey, Senator Menendez said: "Every new piece of evidence builds on to the cloud of suspicion hanging ominously over the circumstances surrounding Al Megrahi's release."
Megrahi is the only person convicted of the 1988 bombing of Pan Am Flight 103 over Scotland, in which 270 people died - most of them Americans.
Mr Salmond defended the Government's actions and said Andrew Fraser, the prison doctor whose role it was to compile and present a prognosis based on Megrahi's medical notes, had followed a process of "complete integrity". He told BBC Radio Scotland's Good Morning Scotland programme: "This is a physician of great experience and I don't think anyone should seriously doubt either his professional or personal integrity."