Chief executive Shaun Harvey has promised the EFL will help investigate an alleged incident involving Fleetwood manager Joey Barton at Barnsley.
Barton is said to have confronted Reds boss Daniel Stendel in the tunnel following Saturday's game, which ended in a 4-2 victory for the home side at Oakwell, and South Yorkshire Police are investigating.
Harvey told BBC Radio 5 Live's Sportsweek programme: "As an off-the-field matter the tunnel is still in the domain of the referee but we will work closely with everybody to ensure it's not a case of who deals with the matter but actually the matter is dealt with properly.
"The police investigation is ongoing so we need to leave the details for them to deal with."
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A South Yorkshire Police spokesman said: "We are aware of something that has taken place in the tunnel after the game and we are investigating."
Police were filmed stopping Barton from leaving Oakwell after the Sky Bet League One game.
Harvey added: "I was stunned when I heard. We have all heard of tunnel fracas as players have left the pitch. It's the first instance I've heard, described as it has been, by those who witnessed it.
"It's disappointing and it comes on the back of a number of challenges which have come to the surface for football to deal with.
"We need everyone who plays a part to lead by example."
Fleetwood issued a brief statement on Sunday morning, which read: "Fleetwood Town have been made aware of an alleged incident following Saturday's game against Barnsley.
"We are currently establishing the facts and will not make any further comment at this time."