Victorians have been warned against a cryptocurrency scam after fraudsters posing as debt collectors convinced victims to deposit more than $50,000 into a bitcoin ATM.

The victims, who are all from the eastern suburbs and believed to be migrants, were told they would be arrested if the amount was not paid.

Police said the four victims were told to take money from their bank accounts and go to Braybrook where a bitcoin ATM, one of a few in Melbourne, is located.

The victims were then given a code and instructed to deposit their money into a certain bitcoin account.