Scammers are exploiting the outpouring of generosity for the Queensland flood appeal.

Charitable Australians are being warned to be vigilant amid reports of fraudulent emails, websites, phone callers and door-to-door collectors seeking funds.

Queensland Police Service have posted messages on Twitter and Facebook urging the public to beware of the "vultures".

Concern follows reports of scammers falsely claiming to be from major banks asking for funds.

In NSW, the State Emergency Service is investigating claims that fraudsters are calling people, claiming to be from the SES, to seek money.

Queensland Deputy Commissioner Ian Stewart said that "unfortunately the vultures have started to come out" and a number of scams were operating, particularly in south-east Queensland.

Some of these involved bogus tradespeople demanding money up-front to clean or paint buildings or clear yards. They then disappear with no work being done.

Other scammers were phoning or electronically contacting householders, telling them they knew best how to handle money from federal and state authorities and then demanding their bank details.

"Do not fall into the trap of handing over any details of that sort. These are just scams," he said.

Police had previously put out warnings about scammers trying to trick flood victims but approaches to people about handling their government money were new and Mr Stewart said anyone approached should contact police so they can thoroughly investigate.

Donations to the official appeal fund have so far reached about $64 million.

- AAP