Details of all those enjoying the First Minister's private hospitality are deleted within 72 hours, once security personnel no longer require them, the Sunday Herald has learned.
Labour and the LibDems last night urged Salmond to publish full guest records to ensure transparency.
The call comes days after the First Minister instigated an external inquiry into his own conduct after he treated a series of SNP donors, including Ayrshire's £161 million lottery winners Colin and Christine Weir, to tea at Bute House. The Weirs gave the SNP a record £1m donation four days after meeting Salmond at the Georgian mansion on September 9 last year. But as they had tea rather than lunch, dinner or drinks, their names were not recorded in official hospitality registers.
After his critics drawing parallels with David Cameron dining with big Tory donors at Downing Street, Salmond referred himself to the former Lord Advocate Dame Elish Angiolini, who will now judge whether he broke the ministerial code.
The row centres on access to Bute House. Salmond's use of it for work is documented while his use of it as a second home isn't – a convenient loophole, say critics. After the Sunday Herald requested names of overnight guests under Freedom of Information, officials said there had been no official guests since Salmond became First Minister, but there had been private overnight guests.The Scottish Information Commissioner accepted the Government had no guest records, but only because the information was "retained for two to three days and then disposed of".
Salmond's spokesman said the record-keeping was consistent with previous administrations, adding: "No donor events and nothing associated with party fundraising take place in Bute House – never has and never will."