Debt-wracked Greece will probably need another EU bailout of tens of billions of euros after its elections, a German weekly newspaper said on Wednesday, citing government and financial sources.

"Even if Greece sticks to its reform path, the country will need fresh money this summer, according to Die Zeit's information," the paper said, citing a sum "in double figures" of billions of euros.

"If a state insolvency is to be avoided, then the Europeans will need to jump in again. The Bundestag (lower house of parliament) may possibly have to discuss a third Greek package again.

"A double-digit billion euro amount is being discussed," the report added.

A precondition for such a third bailout package would be that elections result in a government "that commits itself to further reforms," Die Zeit said.

Greece has been forced to seek international help twice, first for 110 billion euros in May 2010 and then for 130 billion euros earlier this year plus a 107-billion-euro private debt write-off.

The country holds an election on Sunday that is being watched nervously by politicians and markets around the world, amid fears that the leftist Syriza party, which wants to tear up the bailout deals, will triumph in the vote.

If the next Greek government - the forming of which in itself could be a tall order if the results are similar to a first election on May 6 - reneges on its commitments, the flow of funds will cease.

This could precipitate the exit of Greece from the eurozone, experts warn.

German Chancellor Angela Merkel has stressed several times that she wants Greece to stay in the 17-nation eurozone but that Athens must stick to its commitments.