Police have arrested 21 people after raiding a factory in Truganina for allegedly running an illegal casino.

Detectives believe as many as 50 people were attending the western Melbourne factory while the illegal casino was operating.

As part of the raid, police seized cash, drugs, alcohol and gaming tables.

The casino allegedly had a minimum $8000 buy in and had been operating without a gambling licence while serving alcohol from an unlicensed bar.

Westgate Divisional Response Unit Acting Detective Senior Sergeant Thomas McGowan said the police had monitoring the casino for a while.

“This investigation has been going on for several months and it’s been suspected of being open and operating for some time,” he said to the Herald Sun.

Westgate Police Division Inspector Scott Colson said the raid occurred from an ongoing investigation into organised crime.

“We will allege a range of criminal offences, including drug trafficking and firearm possession, have been committed,” he said.

“When significant quantities of cash are seized from organised crime syndicates, we know this deals a hammer blow to their ability to fund further illegal activity.”

A 35-year-old Truganina man, the alleged operator, is expected to be charged with a number of crimes including unauthorised gambling and selling liquor without a licence.

Conducting unauthorised gambling carries a maximum penalty of a two-year prison sentence or a $192,000 fine.

Photo: Casino Table In Close-up View by Aidan Howe available HERE and used under a Creative Commons license. This image has not been modified.