Scottish FA Head of Refereeing Willie Collum admits Rangers should have been given a penalty against Celtic in the Premier Sports Cup final.

In extra-time of Sunday’s final at Hampden, Celtic defender Liam Scales fouled Rangers winger Vaclav Cerny on the edge of the box, with referee John Beaton awarding a free-kick.

Replays showed the infringement occurred on the 18-yard line, and therefore a penalty should have been given.

But VAR duo Alan Muir and Frank Connor failed to intervene.

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Audio from the incident was released on Thursday morning at Clydesdale House on the Scottish FA's VAR Review Show, in which the pair are heard discussing that they think the foul happens “just outside the box."

Muir said: "He's just outside the penalty area. It's not much more than that".

Muir then asked assistant VAR Connor if he agreed, to which he replied: "100 per cent".

Collum told the VAR Review Show: "We acknowledge that it's a really, really poor decision.

"It's an unacceptable decision. The VAR team know that. Everybody in refereeing knows that.

"It's unacceptable. We will do out very, very best throughout coaching and analysis to make sure an incident like this never happens again.

"It's mistake and it's a bad mistake.

"I spoke at the start of the season when I took up this role there would be accountability in refereeing.

"I told the media and the managers that we would deal with things internally. There would be accountability.

"We've been consistent with that throughout the season. If match officials find themselves not involved in future matches or we need to change the profile of a match for somebody, we won't come out and publicly say it.

"A manager doesn't publicly talk about taking a player out.

"We've also got a responsibility to protect the wider group of the referees and the match officials involved in this as well."