Cyprus' public debt took off after they were downgraded by Moody's and friends last year (meaning they were no longer able to borrow). This happened because the EU--in their infinite wisdom--wrote off a €4b loan (in bonds) Greece owed to Laiki (a Cypriot bank). So that's €4b the government lost overnight, and round about €10b it's "lost" since 'cos they can't trade.
Public debt for 2011 was 71.1 of the country's GDP.[1]
[1] http://www.centralbank.gov.cy/media/pdf/AnnualEconomicIndica...