Justice Secretary Kenny MacAskill claimed yesterday that a child killer had been among prisoners freed on compassionate grounds by the previous Holyrood administration, as he defended his handling of the Megrahi decision under pressure from MSPs.

He told the emergency session of parliament that Libya had reneged on a promise to keep the arrival of Megrahi a low-key affair, but he made a pledge to MSPs that he was looking to publish as much correspondence and documents about the affair as possible - including notes of his controversial meeting with Megrahi in Greenock Prison.

He also revealed that in advising him against moving Megrahi from prison to a residence outside, the police had said the security implications would be severe, requiring the use of 48 officers.

While few blows were landed on Mr MacAskill during questions from opponents, Labour did suffer a blow of their own when former minister Malcolm Chisholm undermined his leader Iain Gray by coming resolutely to the defence of last week's decision.

Mr Chisholm said: "Can I regret the politicisation of what is a quasi-judicial decision, and for my part commend the Justice Secretary for a courageous decision, which is entirely consistent with both the principles of Scots Law and Christian morality, as evidenced by the widespread support of churches across Scotland."

He added that, although the scenes that greeted Megrahi's return had caused "revulsion", there was nothing that anyone here could have done to stop that and it was irrelevant to the original decision.

The emergency session had opened with the Presiding Officer pleading for dignity and decorum in the chamber given that the eyes of the world were on Scotland, but some of the exchanges did become fiery, such as when Liberal Democrat leader Tavish Scott lambasted the minister's visit to Megrahi in prison.

"How many more can elect to have the minister visit them in their cell, even if they have a well-paid and well-equipped set of lawyers perfectly able to help them write a letter?" Mr Scott asked. "And doesn't Kenny MacAskill's comment on the need for Scottish compassion mean that no prisoner - however bad their crime - will ever have a request turned down?"

This comment stung Mr MacAskill into his response that among those released on compassionate grounds by former justice minister Jim Wallace was an inmate imprisoned for child-killing.

Mr MacAskill's 20-minute statement was almost identical to his announcement last Thursday but did include a new pledge: "I have already published key material on both the applications for prisoner transfer and for compassionate release. I will now look to publish other relevant material. Some of this can only be done with the permission of others, which we are seeking."

He also added an attack on the scenes in Tripoli last Thursday night, saying: "It is a matter of great regret that Mr al Megrahi was received in such an inappropriate manner. It showed no compassion or sensitivity to the families of the 270 victims of Lockerbie.

"Assurances had been given by the Libyan government that any return would be dealt with in a low-key and sensitive fashion. Advance notice of my decisions was given to the UK and US governments so that they could seek similar assurances."

The Justice Secretary also stressed: "It was a decision based on the law of Scotland, and the values I believe we seek to uphold. It was not based on political, diplomatic or economic considerations," adding: "My decision was made following due process, and according to the law of Scotland. I stand by the law and values of Scotland."

But Mr Gray claimed he spoke for the silent majority in Scotland who were angered by the release, saying of Mr MacAskill: "Does he understand how ashamed we were to see our flag flying to welcome a convicted bomber home? Does he understand how astonished we were when he visited a convicted murderer in prison?"

He insisted that written representations were all that were necessary from Megrahi's lawyers, not a personal visit in prison. "Will he now admit it was his decision - and his alone - to visit al Megrahi? He had no obligation to do so. The Cabinet Secretary has mishandled this whole affair from start to finish."

Conservative leader Annabel Goldie told MSPs: "If Mr Megrahi's condition is so severe that keeping him in prison is inhumane, why could he not have been released to a secure house or a hospice or a hospital in Scotland?

"Is this SNP government seriously suggesting that our Scottish Police who coped so admirably with security for G8 leaders could not adequately protect Mr Megrahi?

"I know he said in his statement that it would take 48 police officers to look after Mr Megrahi in Scotland. That is a small price to pay for just a few weeks. Scotland's reputation on the world stage is worth far more."

But Mr MacAskill pointed to advice from the police that "the security implications of such a move would be severe" and he added that it was a "ludicrous idea to suggest we could send Mr Megrahi to a hospice and turn that into a travelling circus."

He later replied to a similar question from Labour's Karen Gillon, saying: "I was not prepared to foist the encumbrance of Mr al Megrahi on any hospice in Scotland requiring to deal with the terminally ill in their last moments. That would be unfair on any of them. I and I alone - ruled that out."

Tory justice spokesman Bill Aitken accused Scottish ministers of naivety and inexperience in international affairs, resulting in them becoming pawns in a bigger game, while Patrick Harvie of the Greens argued that in the long run it was vital that questions were answered about the safety of the Lockerbie conviction, the way it was obtained, and the process behind the release.

While he welcomed Mr MacAskill's pledge to release as much material as possible, he said it was unacceptable that the UK Government was not prepared to promise the same stance.