Cardiff City have demanded that Crystal Palace's three points picked up in Wales in April should be wiped out.
The relegation strugglers have contacted the Premier League alleging that Palace boss Tony Pulis was aware that sporting director Iain Moody was try to obtain the Cardiff line-up 24 hours before their match.
They claim to have proof that Moody succeeded in his endeavours, and the Premier League has confirmed it will invesitgate the claims.
Palace won 3-0 at Cardiff, a result that went a long way to securing another season in the top flight.
And after last weekend's 1-0 win over Aston Villa, Pulis said: "Irrespective of who or where it has come from, it is pure speculation until the team-sheet comes in.
"Although I try and avoid it myself, I have known managers change the team 10 minutes before the team-sheets have gone in so it is very difficult to say it is definitely going to be that team.
"I'm never, ever convinced what team we are going to play against until that team-sheet comes through the door."
A Premier League spokesman said: "The Premier League has received a formal complaint from Cardiff City and will now investigate the matter."