Maribyrnong Crime Investigation Unit detectives are investigating a series of fraudulent cash withdrawals, totalling more than $20,000.
Police were told a woman attended a bank on Melton Highway, Taylors Lakes about 3.30pm on 22 November.
Investigators believe she produced fraudulent documents and identification to withdraw $2,200 in cash.
The woman attended the same bank about 9.30am on 23 November and withdrew $12,000.
Later in the afternoon, the woman attended a different bank on Douglas Parade, Williamstown just after 4pm.
She produced the documents again and withdrew $6,900.
The woman withdrew a total of $21,100 over two days.
Investigators have released an image of a woman they believe may be able to assist with their enquiries.
The woman is described as Caucasian, medium build, with shoulder-length brown hair.
Anyone with information or CCTV footage is urged to contact Crime Stoppers on 1800 333 000 or make a report online at www.crimestoppersvic.com.au.