Albania's central bank has admitted that some 713m lek (£4m) have gone missing from its reserve.
The cash shortage was discovered during an inventory check of the bank's monetary assets.
Police have arrested two employees of the bank, named as Ardian Bitraj and Mimoza Bruzi, who have been accused of stealing the money from the reserve storage building.
It was not immediately clear how the heist was carried out but the bank, which is in charge of the country's monetary policy, said the cash leaked out over a period of time.
Local media reported that one of the two alleged thieves admitted to taking money out of the reserve over a four-year period. The suspect reportedly claimed to having gambled away all the cash.
However, police are said to be investigating bank transfers involving relatives of both suspects.
Bank officials held a closed-door meeting with lawmakers from the parliamentary committee for economy and finance to discuss the heist.
"Bank of Albania has taken immediate action to repair the damage and step up security levels," Governor Ardian Fullani told a press conference afterwards.
The Bank maintained that its operations had not been affected and it was supplying the country's banking system with the necessary liquidity.
"This incident has affected both the image of the bank and the nation," said the chairmen of the parliamentary committee, Erjon Brace. "We want zero tolerance against all those involved."