Police have busted an illegal casino operating in a warehouse in inner Melbourne.

The Critical Incident Response Team raided the building in Duke Street in Abbotsford just before 10:00pm last night.

The officers seized a large amount of cash, gaming tables, gaming chips and other gambling paraphernalia as well as a small amount of cocaine and cannabis.

The casino's business records were also seized.

Police say 26 people will be charged on summons with being found in a common gaming house.

Inspector Michael Beattie says the raid followed a month-long investigation by numerous police units.

"Behind the rather drab exterior of this factory there is quite an elaborate entertainment area, which included gaming tables, a bar, a band playing and sexually explicit entertainment," he said,

"We will allege that organising attendance at this venue is done through a social media site and we will be alleging that large amounts of money are going through this operation."

A 36-year-old Abbotsford man remains in custody and is being questioned by detectives who are investigating links to organised crime gangs.

Another man was questioned and released while investigations continue.