Tottenham are to file a complaint with the Premier League over Chelsea’s alleged illegal approach to sporting director Frank Arnesen.
Arnesen has been suspended by Spurs and according to press reports Tottenham are set to demand up to £10m in compensation from their London rivals.
Chelsea, who have just been fined for an illegal meeting with Ashley Cole, deny any wrongdoing.
But Tottenham have stated that proper procedures were not followed.
Chelsea claim they wrote to Spurs chairman Daniel Levy before approaching Arnesen and deny breaching Premier League rules.
However, Spurs have explained how the letter to ask for permission to approach Arnesen was also copied to the Dane.
“By definition, Frank was approached prior to the club having had any chance to refuse permission,” said a statement on the club’s website.
Arnesen was suspended by Spurs on Saturday after apparently indicating that he wants to join Chelsea.