The Greek Football Federation on Friday said the sending of a three-page threatening letter accompanied by a bullet to its president was an 'attempted terrorist attack'.
The registered package, which contained the letter and a 9mm bullet, was sent to Vangelis Grammenos at his Athens office on Thursday.
The package was opened by his assistants as he was not at his office at the time.
'The Greek Football Federation condemns in its most unequivocal, unambiguous and unmistakable way...yesterday's attempted terrorist attack on President Grammenos,' the federation said in a statement.
The statement added that 'the newly elected administration of the Federation is not intimidated' and said that 'complete redevelopment, which may upset some, will be completed,' within the Greek game.
Greek anti-blackmail and anti-terrorist units are investigating the contents of the letter and the bullet in order to find the culprits.
Greek media reported that the letter was signed by 'the people of a major team'. Other reports noted that Grammenos has been threatened in the past for his relations with certain clubs and with the current national government.
The government has introduced legislation to clean up Greek football, which has been plagued by accusations of match-fixing and violence.