The death of Abdelbaset al-Megrahi in Tripoli yesterday is a closure of sorts, but only of the diplomatic fracas that accompanied his release from prison in Scotland in 2009. It brings us no closer to solving the mystery of who was responsible for the bomb that brought down Pan Am flight 103 over Lockerbie in 1988. Nor does it offer any resolution to the families of the 270 people who died.

Megrahi was released, after serving eight-and-a-half years of his 27-year sentence, because he had terminal prostate cancer and was judged to have only three months to live. But when he received a hero's welcome from Colonel Gaddafi on his arrival in Libya – and then proceeded to long outlive his Scottish doctors' pessimistic prognoses – his release provoked a major diplomatic incident.

The response in Scotland was mixed, less on the question of whether to be merciful to a dying man than because of doubts as to the validity of the conviction in the first place. In the US, however, there was widespread hostility and the release was widely denounced, not least by President Obama. As the stand-off continued, the allegations grew ever murkier, including claims that Westminster pressed for the deal to protect Britain's trading relationship with Libya. And there were also hints that the release was linked to Megrahi's last-minute decision to drop his appeal.

With his death, the diplomatic embarrassment, at least, is over. But there is unfinished business still. Megrahi's abandoned appeal followed a three-year Scottish Criminal Cases Review Commission investigation that set out six different grounds upon which there might have been a miscarriage of justice, as he had always claimed. Several of the families of Lockerbie victims also believe in his innocence, and the representative of the families of some of the British victims described him yesterday as "the 271st victim". With so many loose ends remaining and so many questions about the original trial unresolved, the Scottish Government should agree to a public inquiry into the tragedy. Mr Megrahi's death is no reason to stop trying to get to the truth.