Arsenal believe Chelsea could be guilty of an illegal approach to Ashley Cole.
The News of the World claimed Cole has attended a meeting in a London hotel with Chelsea boss Jose Mourinho and chief executive Peter Kenyon.
Mourinho denied the allegations, claiming he was in Milan at the time holding talks with Inter’s Adriano.
But Arsenal chairman Peter Hill-Wood said: “It has been reported in a very definite manner and that makes you think something untoward has gone on.”
England full-back Cole is under contract to Arsenal until 2007 so any meeting would be illegal under Football Association rules.
Hill-Wood told the The Sun: “The Premier League rules are very clear on this matter. If the club is presented with evidence that those rules have been contravened I’m sure we will take the matter further.
“These are very serious allegations and we will be investigating the matter as quickly as possible.
“Ashley Cole is under contract to Arsenal for another two seasons and I am sure the club will be talking to him about these reports in an effort to get this matter resolved.
“We know this sort of thing does go on in football and it would not be the first time another club has tried to speak to one of our contracted players.”
Arsenal vice-chairman David Dein stated yesterday: “This is a very disturbing matter and we will deal with it very seriously.
“We’d be very interested to see the evidence obtained.”
Cole’s agent Jonathan Barnett denied the meeting took place.
He said: “Any suggestion that Ashley Cole has spoken to anyone at Chelsea is total and utter nonsense.
“There is no problem between Ashley and Arsenal. Ashley is extremely happy at Arsenal – he has neither asked (for) nor considered a move.”
Dein added: “He is our player and we intend to ensure he remains our player.
“I can assure our fans we are not going to allow this situation to develop into one where Ashley Cole says he wants to go.
“He is our player, we hold his registration and he has a contract to 2007. At this moment, we are in advanced negotiations with him and are close to a new deal.”