For the next two days, David Cameron is on an official visit to the US. His joint oped with Barack Obama in the Washington Post is designed to set the tone for the visit – it seeks to emphasise the strength of the alliance by highlighting what they have in common: international development, Iranian sanctions, condemnation of Syria, and Libya.

However, The Herald has a story today that should shed some light on US-UK relations over Libya. The paper had seen the Scottish Criminal Cases Review Commission (SCCRC) dossier on the Lockerbie bombing case, which seeks to review the conduct of cases post-appeal to determine if there has been a miscarriage of justice.

In this case, the SCCRC found six different grounds that could have constituted a miscarriage of justice and makes clear that had the Crown shared seven key pieces of evidence with the defence, the outcome of the trial could have been different.

Most importantly, The Herald reveals that three of the undisclosed documents related to payments of around $3m made to Paul and Tony Gauci (witnesses for the Crown’s case – Tony Gauci’s identification of Megrahi was crucial to the case against the Libyan) by the US Justice Department.

The defence were not aware of this payment. Had they been, a challenge could have been brought. Apparently, the SCCRC notes that "Such a challenge may well have been justified, and in the commission's view was capable of affecting the course of the evidence and the eventual outcome of the trial."

Given that Megrahi’s trial, appeals and compassionate release were so high profile, the news that witnesses who gave crucial evidence against him had been financially rewarded for doing so by the US government is very important. Megrahi was convicted in a Scottish court, but it seems the influences of other nations on its proceedings weren’t full disclosed.

In the next couple of days, Cameron and Obama are going to show us the light, fun side of foreign policy. This dossier reminds us that there is a darker side to the relations between the states they lead, and that we must never forget it.

Tags: Barack Obama, David Cameron, Lockerbie, Megrahi, Scottish Criminal Cases Review C