Labour has called for Alex Salmond's senior adviser to join him in giving evidence under oath to the Leveson Inquiry into media ethics.
The call for Kevin Pringle to attend with the First Minister follows political pressure on Mr Salmond over his relationship with News Corporation chairman Rupert Murdoch.
Labour says Mr Salmond has not been "straight" with the public about the nature of his dealings with the media tycoon, particularly during Mr Murdoch's proposed takeover of BSkyB.
Last week the Scottish Government revealed that Geoff Aberdein was the adviser named in emails suggesting Mr Salmond was prepared to lobby UK Culture Secretary Jeremy Hunt on the takeover.
Mr Salmond denied any wrongdoing and described the suggestion he would contact Mr Hunt as "email tittle-tattle".
Mr Pringle is also named in Leveson Inquiry documents as a contact with News Corporation representative Frederic Michel, which the Scottish Government said is a mistake that needs corrected.
Labour business manager Paul Martin MSP said: "Kevin Pringle is Alex Salmond's head of media relations. He has spent his working life in media relations. Yet the Scottish Government expect us to believe he had no role in managing the media relationship which Alex Salmond prizes most highly: his relationship with Rupert Murdoch. No one finds that credible.
"It begs the question: why is Alex Salmond so afraid of Kevin Pringle giving evidence on oath to the Leveson Inquiry?"
A statement from the Scottish Government last week drew attention to Mr Pringle's inclusion in Leveson Inquiry papers.
The Scottish Government told the inquiry: "Your schedule describes a telephone call between Frederic Michel and Kevin Pringle on March 2. Scottish Government records and an internal News Corporation email of the same date confirm this was in fact a telephone call between Frederic Michel and First Minister Alex Salmond, which Mr Pringle had no involvement with."
A spokesman for the First Minister said on Monday: "It's a case of another day, another embarrassing blunder from Labour as they flail around in a desperate bid to throw as much mud as possible.
"Their claims are completely unfounded because the fact is this phone call was actually with the First Minister and did not involve any advisers, as we made clear last Thursday when we asked for corrections to the official records of the Leveson Inquiry."