The blog by Mark MacLachlan is now offline
Opposition parties have called on the SNP to hold an inquiry after one of its party workers was discovered using his blog to smear rivals.
Mark MacLachlan quit as constituency aide to Constitution Minister Mike Russell following the revelation.
Labour and the Tories now want SNP leader Alex Salmond to investigate.
Mr Russell said that what had happened was "absolutely unacceptable" but he was happy Mr MacLachlan's departure marked the end of the matter.
The internet page at the centre of the row, called the Universality of Cheese blog, has now been closed.
Mr MacLachlan, wrote under the pseudonym Montague Burton, said he had got carried away and regretted what he had written.
Party officials discovered the 46-year-old had made lurid allegations about the personal lives of politicians and other public figures.
Among those reportedly smeared were Lord Foulkes, the Labour MSP, Paul McBride QC, the lawyer and high-profile Tory, and Labour councillors.
In an official statement Mr MacLachlan, 46, said: "I unreservedly apologise to all the people concerned, and to Mike Russell.
"In getting carried away with my comments, which were very wrong, I have let myself and my colleagues down, and of course I have resigned from my position in Dumfries."
Labour hit out at the former aide's actions, branding his behaviour "outrageous and reprehensible".
Its Scottish leader, Iain Gray, said he believed the issue raised a lot of questions that needed answering.
He added: "Back in May I asked Alex Salmond to get a grip of these 'cyber nats' bloggers. At the time they were spreading rumours about me and other politicians as well. I think Alex Salmond has to come to parliament, apologise, and explain just exactly what has gone one."
Scottish Tory leader, Annabel Goldie, said she was deeply disturbed by the incident and said Mr Salmond should be profoundly concerned.
She added: "I am writing to Alex Salmond to say to him 'look this conduct was completely repugnant, totally unacceptable. You need to instruct an inquiry to be sure that nobody else paid by the tax payer is behaving in a similarly unacceptable manner'."
In response, Mr Russell said that the actions of Mr MacLachlan were "absolutely unacceptable."
He added: "There is no place for anonymous, despicable commentary of this sort in politics and the person no longer works for me. It shouldn't happen in any party. I hate the fact that this has happened.
"I am happy that this is the end of the matter - the person has paid the ultimate price, he no longer works for me."
Liberal Democrat leader Tavish Scott also called for an investigation. He said he wanted Holyrood Presiding Officer Alex Fergusson to look into the matter.
Mr Scott explained: "I'm writing to the presiding officer asking him to conduct a full investigation. We need to know if Mike Russell's aide was using parliamentary computers and time to conduct his odious campaign and whether this is part of an orchestrated online SNP campaign, coordinated from Bute House."