From late 2009 a handful of mainly southern eurozone member states started being unable to repay their national Euro-denominated government debt or to finance the bail-out of troubled financial sectors under their national supervision without the assistance of third parties. This so-called European debt crisis began after Greece's new elected government stopped masking its true indebtedness and budget deficit and openly communicated the imminent danger of a Greek sovereign default. Seeing a sovereign default in the eurozone as a shock, the general public, international and European institutions, and the financial community started to intensively reassess the economic situation and creditworthiness of eurozone states. Those eurozone states being assessed as not financially sustainable enough on their current path, faced waves of credit rating downgrades and rising borrowing costs including increasing interest rate spreads. As a consequence, the ability of these states to borrow new money to further finance their budget deficits or to refinance existing unsustainable debt levels was strongly reduced.
Try to answer this question if possible (otherwise reply "unanswerable"): What had Greece's previous government been hiding?
its true indebtedness and budget deficit