Photographs on Sunday showed PAOK soccer team owner Ivan Savvides, wearing a holster on his waist containing what appeared to be a revolver, walking on the field to intervene in the closing minutes of the home game against Athens side AEK. The incident prompted Greece's sports minister on Monday to announce he was preparing to take action against Savvides.
Savvides, accompanied by bodyguards, walked onto the field at Thessaloniki twice on Sunday, once wearing an overcoat, the second time with the coat off and his holster in plain view. He did not pull out a weapon.
He was held back at one point as he and others remonstrated with the referee, who had disallowed a goal from PAOK's Fernando Varela in the 89th minute. Up to then the match had been a goalless draw.
Images of "persons entering sports grounds armed" harm PAOK and soccer in general, Greek Deputy Culture and Sports Minister Georgios Vassiliadis said in a written statement on Monday.
"Such extreme phenomena call for bold decisions," Vassiliadis said, without elaborating. Greece's state broadcaster ERT said one option being considered was suspending first division fixtures.
"We will not allow anybody to deter us from this path, even if tough decisions are required in consultation with UEFA," Vassiliadis added.
Police said they wanted to question Savvides for unauthorized entry to the soccer field but did not mention they wanted to question him on the holster. A police source said the PAOK boss was licensed to carry a firearm.
The referee, Georgios Kominis, reviewed his decision after the game and allowed the goal, state TV reported.
Savvides, one of the richest people in Greece, was born in Georgia of Greek heritage and is a former member of the Russian parliament. He has holdings in assets ranging from Thessaloniki port to tobacco and media companies.
Field invasions are relatively common during rowdy Greek soccer fixtures.
A derby between PAOK and Olympiakos Piraeus was called off last month after Olympiakos coach Oscar Garcia was hit by a roll of paper thrown from the stands.
Authorities say they are committed to cleaning up the sport.
Reporting By Michele Kambas and Lefteris Papadimas; Editing by Gareth Jones and Andrew Heavens/Reuters.