Detectives from the PSNI Economic Crime Unit today carried out the eight searches and arrested two men.
Officers searched business and residential properties in the Lurgan, Dungannon, Antrim and Belfast areas. Two men, aged 39 and 69, were arrested and are being questioned at Lurgan police station.
Detective Chief Inspector Ian Wilson, from the Economic Crime Unit which is part of Reactive and Organised Crime Branch, described the operation as significant.
He added: “We have seized a significant number of illegal gaming machines, related technical equipment, documentation and a substantial amount of cash and criminal property.
“We believe there is a link between illegal gambling and money laundering which feeds other forms of crime in our community. This illegal gambling is often used by criminals as a means of laundering money obtained from organised criminal activity and plays an important role in other forms of acquisitive and organised crime.
“We are determined to tackle it. Our enquiries will continue for some time and I would appeal to anyone with information about money laundering or illegal gambling to contact police.”