DOUGLAS Ross has claimed he was "physically assaulted" and verbally abused by the SNP's parliamentary business minister Jamie Hepburn.
The Tory MSP raised a point of order at the end of First Minister's Questions alleging there had been an altercation.
Ross noted that Hepburn was not in the Chamber on Thursday.
It is believed the clash was over Ross's calls for a further debate on seagulls.
Ross told journalists that he had reported the incident to the Scottish Parliament's chief executive, and he would be speaking to police on Thursday afternoon.
"Presiding Officer, you know what I'm going to mention as I emailed you this morning seeking to raise this at First Minister's questions," Ross said.
"First Minister, as I left the Chamber yesterday, I was physically assaulted and verbally abused by your minister for parliamentary business, Jamie Hepburn.
"This is the point I would make to the First Minister, I'm wondering if the First Minister will make a statement and take the opportunity to say that he has a zero tolerance approach to threatening and intimidating behaviour.
"I have raised this yesterday afternoon, with parliamentary officials, and I notice that the minister for parliamentary business is not in the chamber this afternoon. Will he be making a statement on this incident later today?"
Speaking to The Times, Ross said: “The minister grabbed me on the shoulder and held on to me all the way out of the Chamber.
"At the same time he was continually swearing at me and getting more and more aggressive. He just wouldn’t give up.
“He lost his temper in a big way and there is no way that behaviour can be tolerated in any workplace.
"Jamie Hepburn has a duty to listen to members and respond to them — that is his role as parliamentary business manager.
"However it seems that if he disagrees with you he resorts to violent, threatening and intimidating behaviour.”
In response, Presiding Officer Alison Johnstone said it was a "very serious allegation".
She added: "It is important that it is dealt with through the appropriate processes.
"I expect all members to take their responsibilities under the Code of Conduct seriously.
"And when anyone considers that the conduct of a member hasn't met the terms of the code a complaint can be made, and complaints in relation to most matters covered by the code, including a complaint of this nature, would be initially investigated by the commissioner for ethical standards and public life in Scotland.
"Recommendations coming from any complaints may of course come to this Chamber in due course, therefore I must avoid any comments that may compromise that."
Johnstone added that it was a matter for the First Minister under the ministerial code.
When it was put to Hepburn that it had been alleged that he pushed Ross and swore, he told The Times: “Has it now? I did not push Douglas Ross.”
The SNP have been contacted for comment.
A spokesperson for the First Minister said Swinney was not aware of the allegations before Ross stood up in the chamber.
