The Crime and Corruption Commission have charged four men with fraud and money-laundering offences following an 18-month investigation into a Brisbane-based law firm.

On Sunday, the CCC and Queensland Police executed search warrants at residential addresses across Brisbane as part of the investigation named Operation Stockade.

Four men were charged by the CCC on Sunday following an investigation into a Brisbane law firm. Credit:File

It is alleged some of the men charged were involved in serious fraud offences against Legal Aid to the value of about $340,000 and failing to comply with the Legal Profession Act 2007 in relation to the requirement to deposit over $750,000 into a trust account.

It is also alleged the men laundered the proceeds of serious criminal offences.