Anti-terrorism officers were on Friday examining an envelope containing two bullets that was addressed to Bank of Greece Governor Giorgos Provopoulos but was stopped by security guards before reaching his office.
The bullets were traced by a metal detector that checks all incoming mail, according to sources who said they were to be examined by police forensics experts.
A second envelope, also containing bullets, was also sent to Mega television channel presenter Yiannis Pretenderis, sources said.
The incident came a day after Provopoulos said that certain Greek banks may need some additional capital once the stress tests conducted by BlackRock Solutions are published. The bank governor also called on the country's politicians to avoid heated confrontation ahead of European Parliament and local government elections in May, urging them to back a financial recovery effort through its "last mile."
In February last year, Finance Minister Yannis Stournaras received a single bullet in an envelope containing a threatening note. A group called Cretan Revolution later claimed responsibility for sending the envelope in a protest against tax increases.