Authorities say he allegedly used the money to fund side businesses, real estate transactions, and cover personal expenses. The money was also reportedly used to operate a consulting business, Delval Consultants LLC.
Agha Hasan, 41, was charged with theft by deception, computer criminal activity, misapplication of entrusted property, and other related offenses.
Investigators claim that Hasan stole $998,188 from a customer over six years.
The investigation began last year after fraud investigators for Santander Bank contacted police about suspicious transactions that were reportedly done by Hasan.
Hasan had recently been fired from his position at the Mount Holly branch office, authorities say.
Police later found that Hasan, who had been working at the bank since 2014, allegedly befriended the customer and gained his trust by offering to help with bill paying.
Authorities say as their relationship progressed, Hasan began visiting the customer's home, obtaining blank checks that the customer had signed, and having the customer approve wire transfers.
Hasan is also accused of using the customer's account to make significant cash withdrawals and disbursements at the time.
Police believe Hasan used the customer's funds to deal with personal expenses and business ventures, such as the management and operations of gas stations, car washes, and convenience stores.
Hasan was taken into custody Tuesday at his residence in Bordentown Township, New Jersey. He is now being held at the Burlington County Jail pending a detention hearing.