A year after his release, it’s becoming increasingly obvious that the Lockerbie bomber Abdelbaset al Megrahi did not take full advantage of the medical treatment he could have received while he was in jail in Scotland.

What is not at all clear is why.

Megrahi declined to undergo chemotherapy in Scotland. He discussed it with doctors but told Kenny MacAskill he would need his family’s support when it started. At the time his family were in Libya.

Chemotherapy had the potential to extend his life by months. After he returned home to Libya on August 20, he began the treatment.

A document published by the Scottish Government appears to provide evidence that Megrahi was not a model patient before his release.

In notes of a meeting on July 22 last year, it is reported that doctors were talking to Megrahi about new treatment and encouraging him “to take his medication regularly” – suggesting, of course, that he was not.

Just days later, his condition began to undergo such a dramatic turn for the worse that it appears to have been the deciding factor in the release.

The prognosis that Megrahi had three months to live came from Dr Andrew Fraser, director of health at the Scottish Prison Service.

• MacAskill: Releasing Megrahi 'hardest decision I've ever had to make'

In his report on the case, Dr Fraser writes that cancer specialists believed Megrahi had only “months left to live” but none was willing to be as precise as three months.

He then states that another doctor, presumably the jail’s GP, had told him Megrahi’s clinical condition had “declined significantly”.

In the next sentence, Dr Fraser says: “The clinical assessment, therefore, is that a three month prognosis is now a reasonable estimate.”

The “significant decline” began in the week beginning July 26 – just four days after it was reported that the Scottish doctors were talking to Megrahi about new treatment and encouraging him to take his medicine.

In between – on July 24 – Megrahi had applied for compassionate release.

Had he, as some believe, simply turned his face to the wall? Or was there another, more sinister, explanation?

A government source with inside knowledge of the case disputes that Megrahi “refused” chemotherapy or manipulated his illness.

He points out that, at the time, the Libyan was at the centre of an immensely complicated and highly charged situation. His appeal and the applications for prisoner transfer and compassionate release were ongoing.

The insider suggests that the Libyan’s decision not to go ahead with chemo at that stage was understandable.

Megrahi’s medical records might shed further light on the issue but the Scottish Government says they can’t be released because of patient confidentiality.

When he was freed, the Lockerbie bomber moved from a cell block in an Edwardian jail in the wet west of Scotland to his plush home in north Africa.

He returned to the love and support of his family and to a land apparently convinced of his innocence and heroism. He started chemotherapy and every other treatment possible.

Senior government sources in Scotland say its decision had to be based on Megrahi’s condition last August – not what might happen if he was freed.

They would have known his return home could extend his survival. They must never have imagined just how long that would be.

And as things stand, there is no solid evidence that Megrahi's choices about his treatment last summer were a deliberate ploy to get out of jail.