Premises in Lisburn were searched during a police operation into money laundering and illegal gambling last week.
Machines and cash worth more than £500,000 were seized during an operation involving premises at Shaftesbury Square, Lisburn Road and Lisburn.
Detective Superintendent Andrea McMullan, said: “Following a protracted investigation, detectives and experts from the Gambling Commission UK believe casino and high stake gambling machines were being operated in these premises in breach of the relevant licences.
“In addition to the substantial amount of cash seized, we believe the three roulette machines have a value of £100,000 each,” she said. “We seized a further 130 smaller gaming machines which are worth around £1,000 each.
“We have worked with District policing colleagues and partners in the Gambling Commission and Immigration Enforcement to stop what we believe were premises being used for illegal gambling and money laundering.
“This multi-agency operation should serve as a clear warning to those who think they can operate outside the law that police are determined they will not succeed.”
More than 100 illegal gambling/gaming machines and three casino roulette machines were seized along with around £200,000 in cash. The roulette machines are worth an estimated £100,000 each.
A 63-year-old man from Lurgan was arrested on suspicion of managing and organising illegal gambling and money laundering.
He was bailed to attend Musgrave Police Station on March 11. Officers from Home Office Immigration Enforcement also arrested a man in his 40s.