The penalty imposed on Melbourne's Crown casino is believed to be the largest of its kind issued by regulators in Australia, according to anti-gambling advocates.
Regulators found that buttons had been covered up on the slot machines, reports the BBC.
Crown has been hit by other damaging allegations in recent times.
The Victorian Commission for Gambling and Liquor Regulation (VCGLR) said the casino had used "blanking plates" on 17 machines during a trial programme last year, meaning that gamblers were left with only maximum and minimum options.
"This is the largest fine the commission has issued to Crown and reflects the seriousness with which it considers the matter," it said in a statement.
Gamblers lose more money per head in Australia than in any other nation.
Last year, MP Andrew Wilkie presented whistleblower statements to parliament which alleged the casino had altered its machines and breached player regulations, reports the BBC.
Crown won a landmark court case in February against a former gambling addict who argued that she had been misled by "deceptive" design features in one of the casino's gaming machines.
(This story has not been edited by Social News XYZ staff and is auto-generated from a syndicated feed.)
