The new governor of Bangladesh’s central bank, Ahsan Mansur, calculates that about $17 billion was siphoned from the country’s financial system in the 15 years before the government of Sheikh Hasina collapsed in August.

Other economists guess that the true value looted during Ms. Hasina’s rule, before she fled the country, could exceed $30 billion. But no one can say for sure. Using a web of financial schemes, Mr. Mansur said, the perpetrators in the government and at some of the country’s biggest companies pulled off what was effectively the largest bank heist in the history of money. And they did incalculable damage to Bangladesh’s economy.