Leigh Griffiths is now at the centre of a police investigation after he kicked a flare into St Johnstone fans.
The Dundee striker reacted after the visiting support hurled abuse at the on-loan Celtic man by booting the smoke bomb into their section.
It came during the Dark Blues 2-0 Premier Sports Cup quarter final defeat to their Tayside rivals and trophy holders.
Footage emerged on social media after the incident and a police spokesperson said no injuries or complaints had been reported - but that they have launched an investigation.
The spokesperson said: "We are aware of an incident involving a small number of smoke devices at Dens Park, during the match between Dundee and St Johnstone Football Clubs on Wednesday, 22 September.
"There were no injuries and no complaints have been made to police at this stage.
"Enquiries into the matter are ongoing.”
Griffiths - on loan at Dens Park from Celtic - is already set to face an SFA hearing over the incident.
St Johnstone won the game thanks to goals from Shaun Rooney and Ali Crawford as they look to hold on to their silverware.
