The Cardiff City owner Vincent Tan has urged the Premier League to investigate his allegation that Crystal Palace obtained information about their starting line-up for last weekend's relegation showdown by "unethical means".

Cardiff have written to the Premier League's chief executive, Richard Scudamore, complaining that Crystal Palace's sporting director Iain Moody used his contacts at the club to attempt to find out which players would start the match for Ole Gunnar Solskjaer's side – Moody was given the wrong line-up.

Crystal Palace won the match 3-0 to move seven points clear of the relegation zone and leave Cardiff six points from safety with just five matches remaining.

Tan is currently in litigation with Moody after firing him from his role as head of recruitment in October and Moody is reported to have been refused entry to the directors' box at the City of Cardiff Stadium on Saturday. The Premier League has confirmed that Cardiff have written to Scudamore but they must make a formal complaint to take the matter further.

Moody was hired by Palace in November, weeks after leaving his post at Cardiff when Tan brought in Alisher Apsalyamov, a 23-year-old from Kazakhstan with no previous football experience. He and former manager Malky Mackay were accused of "imprudent and careless management" by Cardiff's chief executive, Simon Lim, in February after spending in excess of £8.5m on Danish striker Andreas Cornelius, who returned to FC Copenhagen in the January transfer window for a cut-price fee.