The extradition to Libya of Muammar Gaddafi's spy chief Abdullah al-Senussi brought a rare moment of unity among Lockerbie relatives and campaigners normally deeply split on Libya's role in the bombing.
They agreed that Scottish police and prosecutors should make strenuous efforts to question Senussi about his links to or knowledge of the atrocity, which killed 270 people in December 1988. But they disagreed about why.
Susan Cohen, whose daughter Theodora, 20, was one of 35 Syracuse University students killed in the bombing, said it would be "excellent" if Scottish investigators succeeded in meeting Senussi. "I would thoroughly urge them to do so," she said.
In particular, Cohen said, Senussi could confirm the guilt of Abdelbaset al-Megrahi, the sole person convicted of the bombing, who died of cancer this summer. He could also implicate senior figures in the Gaddafi regime.
She said claims by Megrahi's supporters and other Lockerbie relatives that he was innocent and that the atrocity was committed by another state such as Syria or Iran were "goofball theories" without any evidence.
"My fear is that everybody would have put Lockerbie on the backburner and not pursue the case," she said. "I don't suspect there's some vast conspiracy and they're afraid of what might come out, but Gaddafi is dead and Megrahi is dead – it's easier to deal with the present and easier things, so they don't really want to do this.
"It's vital to interview Senussi. I would hope they will be interviewing others. I think it's extremely important that we know. We should know as much as we can and there may be other people [in Libya] who can be indicted – and if that is the case, we need to do that."
However, Jim Swire, a senior figure among the British bereaved families, is adamant that Megrahi was innocent. A leading member of the Justice for Megrahi campaign, which is discussing reopening Megrahi's appeal against his conviction with his surviving sons, Swire said there had been theories for some years linking Senussi to Lockerbie.
One allegation was that Senussi and Moussa Koussa, the Libyan former foreign minister, who fled Tripoli with the help of western agencies before Gaddafi's death, had taken control of several bombs built by a Palestinian terrorist group, PFLP-GC, that were missed in raids by German police.
Moussa Koussa agreed to be interviewed by Dumfries and Galloway police and Crown Office prosecutors early last year, but is thought to have offered very little new information about Lockerbie or Megrahi. Swire said he was sceptical about the theory, but added: "It's quite possible that Libya played a part in Lockerbie. It's very clear that Megrahi didn't.
"The two people from Gaddafi's regime who seem to be in the frame are Senussi and Moussa Koussa. Moussa Koussa clearly had a relationship with western intelligence because he was allowed to fly to Britain and then the Middle East, where he now lives the life of Reilly. [The] suspicion is that Senussi and Moussa Koussa may have set up the use of those devices for Lockerbie."
John Ashton, author of Megrahi's authorised biography, [Megrahi:] You are my Jury, said other sources believed Senussi was simply a security "enforcer" rather than a spymaster of Moussa Koussa's rank. "Megrahi never hid the fact that he was related to Senussi," Ashton said. "Although he never discussed Sennusi's alleged role in the bombing, he was convinced that Libya – and therefore Sennusi – was not responsible for it.
"Western intelligence sources and the US state department always claimed that Senussi was Megrahi's boss. If that's the case then the Scottish police should be moving heaven and earth to get to him. However, I take those claims with a huge pinch of salt, as the evidence against Megrahi is highly flawed. If the police do get to Senussi, they may well be very disappointed."