ZENIT St Petersburg could be investigated by Uefa after one of their former players admitted bribing a referee in a Uefa Cup match between 2005 and 2008.
Russian club Zenit defeated Rangers 2-0 in the Uefa Cup final at the Etihad back in 2008.
But their former centre-half Erik Hagen has claimed that match-fixing was rife at the club during his time there.
The 38-year-old Norwegian international spent three seasons at St Petersburg, between 2005 and 2008.
And he has alleged that he and his Zenit team-mates paid a referee £1,800 to secure the outcome of a Uefa Cup match.
Hagen says that he and his fellow players each received a £7,200 "bonus" from their club.
Speaking to Norwegian daily newspaper VG this week he said: "I can't remember which match it was. I asked: 'What's going on?' They just said: 'You got to get used to this because that's how it is'."
The defender was not in the squad when Dick Advocaat's expensively-assembled side defeated Walter Smith's team in the Uefa Cup final in Manchester six years ago.
But Uefa admitted they could look into the matter retrospectively if any wrondoing was to be discovered.
A spokeswoman for the Eurpopean footballing body said: "We can't comment on individual cases unless our disciplinary committee has made a decision.
"But the integrity of the game is of paramount importance to Uefa and there are procedures that we can take.
"We are looking into a lot of matches which took place in previous years.
"We have punished and will continue to punish very harshly anyone who is manipulating the result of a match.
"We have collaborated with police authorities to make sure that these criminal activities are tackled."
Hagen has stressed he would repeat his allegations to Uefa officials if they contact him.
He said: "I will tell them the same thing if they ring me.
"Someone has to be the first to do this.
"There are lots of rumours about corruption in international football."
Evgueny Gusev, a spokesman for Zenit St Petersburg, has denied the claims.
He said: "We are deeply astonished by the statement of Erik Hagen.
"Zenit has always followed and follows the principles of fair play and proves its worth only on the football field."