The Justice Secretary has been asked to apologise for not informing Parliament of prison disorder at a youth institution last month.
Last week, the Scottish Prison Service revealed to BBC News that the worst prison disorder seen in Scotland in a decade erupted at HMP and YOI Polmont in September.
The incident, which involved around 30 inmates, required additional officers from four other jails to help restore order.
Linda Pollock, chief executive of the Scottish Prison Service (SPS), told BBC News it was an example of “bubbling tension” caused by overcrowding at the facility.
The incident happened on September 26, with MSPs unaware until the BBC reported it last week.
I think it is appalling that didn't even cross your mind to think about reporting to Parliament
Speaking at a Criminal Justice Committee pre-budget scrutiny evidence session, Justice Secretary Neil Gray was questioned on his decision not to inform Parliament on the incident.
Scottish Tory justice spokesman Stephen Kerr said he thought “an apology would be more appropriate”.
Mr Kerr continued: “If a Conservative home secretary had sat on information about the worst prison riot in a UK prison for six weeks and not informed Parliament, and if we’d had to learn the details of such an incident through the media, the first person, rightly, on his feet on the other side of the chamber, that on the occasion when they finally ‘fessed up, would be Neil Gray.
“That’s why I think it is appalling that didn’t even cross your mind to think about reporting to Parliament.”
Mr Gray said would “reflect” on the dissemination of information.
He said: “My first thought is the safety of our prison system, the safety of our prison officers, and those that are incarcerated, and that is the perspective on which I take the discharge of my duties.
“Of course, I am accountable to this committee, I am accountable to Parliament, and I am feeling that accountability this morning, as the First Minister did yesterday.
“There is no desire to (not) be in any way transparent or as transparent as we possibly can be in operational matters such as this.
“As I’ve given as a commitment, we will reflect upon the dissemination of information on operational decisions and matters such as this to ensure that the committee is given the necessary information it needs.”
Police Scotland is continuing to investigate the incident at YOI Polmont.
A Scottish Prison Service spokesperson said: “The safety and security of those working and living in our establishments is a key priority, and our staff responded to the incident at HMP & YOI Polmont with great professionalism, care and dedication. We provided regular updates for Scottish Government, as well as responding to media queries.”
Police Scotland has been approached for comment.