Already some 3 billion/- is believed to have been stolen from the National Bank of Commerce Limited, Tanzania's largest commercial bank, as part of the financial services crime.
According to latest THISDAY findings, graft investigators from the Prevention and Combating of Corruption Bureau (PCCB) last Friday questioned at least seven senior officials at NBC's headquarters in Dar es Salaam in connection with the theft of billions of shillings.
"Corruption investigators from the PCCB spent several hours questioning senior NBC officials in Dar es Salaam from the credit and security documentation departments about the involvement in the matter," a well-placed official told THISDAY.
She added: "Some senior bank executives and officials are accused of not following standard procedures in the execution of their duties, leading to the huge theft of funds."
It is understood that a preliminary audit has discovered that some bank officials approved dubious payments, counter to bank policy.
An internal probe at NBC has already led to the transfer and suspension of several bank officials.
It is alleged that some officials at the bank's headquarters and branch offices may have colluded in the massive theft of funds.
NBC has 56 branches across the country and employs more than 1,400 workers.
PCCB director-general Dr Edward Hoseah, has already confirmed to THISDAY that a preliminary investigation shows the problem to be much bigger and complex than initially thought.
Officials close to the investigation say several bank officials and private businessmen could face criminal charges as a result of the ongoing corruption investigation.
The South African-based ABSA Group Limited, which owns 55 percent of the shares in NBC, recently brought a team of fraud experts from Johannesburg to investigate allegations of corruption and theft of billions of shillings at its Tanzanian subsidiary.
The Tanzanian government is the second biggest shareholder of the bank with a 30 percent stake, while the International Finance Corporation (IFC), a private financing arm of the World Bank, owns the remaining shares.
A team of about 10 fraud experts dispatched by ABSA Group Ltd. to Tanzania have already spent several days at NBC's headquarters in Dar es Salaam to analyse systems and documentation and grill bank employees.
"A number of NBC employees have been suspended with full pay pending the outcome of the ongoing investigation," said another source who asked not to be named.
"ABSA is keen to establish if the thefts were a result of isolated cases by a few bad apples or if the problem is much bigger than that," he added.
In one incident, some senior NBC officials at the bank's Corporate branch along Azikiwe Street/Sokoine Drive were accused of involvement in making "ghost transactions" amounting to 900m/-.
The dubious payment was linked to Ino Texan Investment Company, which maintains account number 011103033038 at the bank.
"The 900m/- ghost payment at the Corporate branch embarrassed NBC executives because it occurred literally right under their noses," said another well-placed source. The NBC Corporate branch is on the ground floor of the bank's headquarters, with the bank's senior management staff occupying offices on the upper floors of the same building.
At least two officials at the NBC Corporate branch were suspended from work and received warning letters as a result of the fraud.
"You are being reinstated while investigations on an alleged disciplinary offence are continuing -- management is therefore CAUTIONING you so that you become more vigilant in the execution of your duties," read part of a letter sent by NBC Ltd to one of its senior employees who was suspended only to be re-instated after a few days in February.
"Please take note that upon completion of the investigations, in case of being implicated in any misconduct, disciplinary action will be instituted against you," the letter concluded.