The Commonwealth Bank is referring about 100 of its customers to police for criminal prosecution as a result of the recent ATM glitch that allowed people to overdraw their accounts, the head of the NSW Police fraud squad says.

Meanwhile, in Victoria, police confirmed that the bank referred two customers for investigation, who had been summonsed to appear in Melbourne Magistrates Court on May 13 charged with theft.

The revelations come after the bank was accused in a report on ABC radio’s AM program this morning of using “unfair and heavy-handed tactics” when trying to recover the funds that were overdrawn from accounts last month after the bank deliberately took its ATMs offline following a database maintenance glitch.

The bank, which announced a $3 billion profit for the half year ended December 31, 2010, has written to customers – including welfare recipients – threatening them with legal action if they do not repay the money in full and has also closed accounts without notice.