Convicted crime boss Panayiotis Vlastos, who was injured in a thwarted attempted to escape Trikala Prison in central Greece by helicopter last month, had been planning a breakout since last summer, according to authorities who told Kathimerini that they had a tipoff that a hot-air balloon might be used in the operation.

Authorities believe that they thwarted a planned escape attempt in June by Vlastos, who was to undergo a nose operation at Larissa’s main hospital. At the last minute, they transferred the planned surgery to Thessaloniki’s Ippocrateio Hospital to foil his plans. “The police were certain Vlastos would try to escape,” a Justice Ministry official told Kathimerini. Authorities added that they had been informed that the crime boss would try to break out using “an alternative mode of aircraft” such as a hot-air balloon. Prison managers responded to this intelligence by reinforcing the barbed wire surrounding Trikala Prison yard in August.