The consequences of Greece's default on its $1.7 billion IMF loan payment may already be damaging the country's fragile economy with reports that the International Monetary Fund has ordered US tour operators to withhold payments to Greek hotels.

According to Greek blogger Alex Andreou, US tour operators have been told to, "Withhold payments to Greek hotels for services used, by order of the IMF."

"To crush us is their aim," tweets Andreou.

He links to a Skai TV report, one of Greece's mainstream news channels, which suggests that the payments are instead being redirected directly to the IMF to pay off the country's debt. The report cites the head of the Association of Athens Hoteliers, Yiannis Retsos.