League chiefs will decide whether the complaint should be taken forward - it is understood there remains uncertainty about whether any regulation would have been breached even if the allegation was proven.
If the complaint is taken forward it could be dealt with by either the Premier League's board or more likely an independent commission.
Cardiff's letter centres on the circumstances surrounding the alleged leaking of their team.
Palace sporting director Iain Moody worked for Cardiff until earlier this season before taking up a post at Selhurst Park in November.
It has been reported that Cardiff believe Moody might have used his contacts at the Welsh club, or close to Cardiff, to find out which players would start against Palace.
Moody, though, has rejected the allegations as "incredibly, extraordinarily untrue" and Palace have also denied the claims.
According to the BBC, the letter from Cardiff's club lawyers runs to five pages and claims the club have proof Ole Gunnar Solskjaer's starting line-up was leaked.
Source : PA
Source: PA