Greece's oldest football club Panathinaikos have been banned from European competition for three seasons for failing to pay their debts, UEFA has announced.
The Athens-based club were given a suspended sentence by UEFA's Club Financial Control Body, the panel that oversees the governing body's financial fair play rules, in December and told they had until March 1 to settle their unpaid bills.
On March 19, however, the panel's investigatory chamber concluded that Panathinaikos had still not paid these unspecified debts, which meant the December punishment became active.
As well as missing out on European club football for the next three seasons, the club must also pay a €100,000 fine that was originally suspended, having already been ordered to pay the same amount in December.
In a statement, UEFA said the sanction "shall take effect immediately."
National champions 20 times, Panathinaikos are Greece's most successful side in European club competition. They were European Cup runners-up in 1971 and reached the semi-finals of the same competition in 1985, when they lost to Liverpool, and 1996.
This season, however, they went out of the Europa League in the play-off round.