Uefa has threatened Shakhter Karagandy with disciplinary proceedings if they continue to perform the ritual slaughter of animals around games.

The Kazakh champions caused a stir when they slaughtered a sheep at the Astana Arena the day before last Tuesday night's 2-0 Champions League play-off first-leg win over Celtic, leading animal rights group PETA to express its outrage in a strongly worded letter to Uefa president Michel Platini, urging the organisation to punish Shakhter.

There were concerns that Shakhter would repeat the ritual at Parkhead in the return leg this evening and, although it is now clear that will not happen, European football’s governing body has made it clear that disciplinary proceedings will be launched if the practice is repeated.

In a letter to Shakhter executive director Yerden Khalilin, Uefa competitions director Giorgio Marchetti said: "We were informed that an animal slaughter took place at some point prior to the Uefa Champions League fixture involving FC Shakhter Karagandy and Celtic FC at the Astana Arena on Tuesday 20 August 2013.

“Although certain practices may be culturally rooted, they have no place in or around a sporting arena or event. In this context, I would like to make you aware that animal slaughter on a football pitch or in a stadium before, during or after a Uefa competition match - or with reference to a Uefa competition — is totally improper, and will not be tolerated.

“In case of re-occurrence, it will inevitably lead to a full investigation by our disciplinary bodies.”

The news was welcomed by PETA associate director Mimi Bekhechi, who had written to Platini on Thursday asking him to "use your influence to stop any further slaughter in this season's Champions League and Europa League so that such prestigious competitions are not tainted by such horrifying cruelty".

“We’re very grateful for Uefa’s swift and firm action condemning such cruel and archaic practices,” she said.

“Uefa has sent a clear message that there is absolutely nothing sporting about violence towards animals.”

Shakhter boss Viktor Kumykov had suggested at yesterday's press conference the sacrifice would be repeated.

But a Celtic spokesman confirmed later in the the day that no ritual would take place.

“Clearly this would not happen,” they said.

“Shakhter have spoken to the club and said this is a misunderstanding and made it clear they have no intention whatsoever of doing anything like this.”

Earlier Kumykov’s pre-match press conference at Celtic Park took a surreal turn when the subject was broached.

Speaking through an interpreter, the Russian said: “All I can say is that every team and every club has its own pre-match traditions and rituals.

“Celtic must have their own. We will try to respect our traditions and those traditions have been in place even before we came to the club.”

Asked if the ritual would take place, he replied: “Possibly, yes.”

Then, when asked where he planned to get the sheep, Kumykov, to laughter, replied: "As far as we know in Scotland the agriculture is very developed so it shouldn't be an issue to find a sheep."