UEFA president Michel Platini  warned today that the career of any player convicted of match-fixing would be over, as Euro 2012 begins in the shadow of fresh illegal betting allegations in Italy.

UEFA is also due to announce its decision on alleged match fixing involving a Malta-Norway match.

"They won't play football again," the former France captain told a news conference in Warsaw, where co-hosts Poland take on Greece in the Polish capital in the tournament's first match on Friday.

Italy has been rocked by fresh claims of illegal betting in the national game, which led to the arrests of several top players, including Lazio captain Stefano Maurio, and a dawn raid on the national team's pre-Euro training camp near Florence.

Platini, whose former club Juventus were relegated from Serie A after a previous scandal in 2006, was unequivocal about the penalty for guilty parties, describing as "shocking" the possibility that professional footballers could throw games.

The quadrennial European championships are being held in eastern Europe for the first time and organisers have had to face a wide range of issues from infrastructure and accommodation problems to fears over racism and football hooliganism.

Platini acknowledged that there have been organisational difficulties but praised Poland and Ukraine for tackling them.

On racism fears, which have prompted warnings from foreign governments such as Britain and seen the families of two black England players opt to stay at home, Platini said the problem was not confined to football.

"Across the world and Europe in particular, you can see that over the last few years there's been more and more nationalism and you see it at a lot of matches," he told reporters.

"It's easy to point the finger at Ukraine and Poland for racism but all countries are faced with the same problem... We've done a lot of things but it's not a football problem, it's a social problem."

Ukraine in particular has responded angrily to suggestions that far-right gangs had found fertile recruiting grounds at football matches but the row has refused to go away.

Italy's firebrand young striker Mario Balotelli recently threatened to walk off the pitch if he was racially abused by supporters.

Platini declined to say whether UEFA would support such a reponse, instead insisting that it was up to the match referee, who has the power to temporarily suspend the game.

He also declined to say whether he backed a boycott by European Union leaders of matches to be played in Ukraine because of the alleged mistreatment of opposition leader Yulia Tymoshenko, in jail on what critics say are trumped-up graft charges.

"It's up to them," said Platini. "UEFA is not a political organisation. We organise competitions and the development of football around the world."