"Greece relied on Iran for more than half of its oil imports during some months last year after traders and oil majors pulled the plug on supplies and banks refused to provide financing for fear that Athens
would default on its debt."
Unfortunately, Iran has just stopped a shipment of oil to Greece:
"Oil tankers that had come to transfer 500,000 barrels of Iranian oil to a refinery in Greece had to go back empty-handed after Iran refused to give the shipment,"
However, Hellenic have denied the veracity of this story :
"That has nothing to do with us ... all supplies from Iran have been processed normally,"
Well, they would have to deny this wouldn't they?
They are currently negotiating for supplies of oil from elsewhere, any admission that their supplies have been cut will negatively impact those negotiations and cause panic buying in Greece.
Beware denials and irrational optimism from Greek oil companies!