Alvin Chau, the founder of Suncity Group, was arrested in November 2021 on a warrant based on accusations that he ran an illegal cross-border gambling syndicate.
Macau is the only place in China where casinos are legal, and junket operators form a key part of its gaming industry, facilitating gambling for wealthy Chinese outside the former Portuguese colony.
The casinos account for more than 80 per cent of the government's income.
Mr Chau and some others were accused of running a syndicate that caused a loss of about £817m in tax revenue to the Macau administration between 2013 and 2021. Prosecutors argued that they made illegitimate profits through operating side-betting activities.
He faced nearly 290 charges in one of Macau's biggest criminal cases in years.
Suncity was one of the biggest junket operators in Macau prior to the coronavirus outbreak and reportedly accounted for about 25 per cent of total gaming revenues.
Mr Chau pleaded not guilty to all wrongdoing during his two-month trial. His lawyers argued that he did not operate any illegal gambling or commit money laundering, adding that his business in the Philippines was permitted by local authorities.
The company did not promote gambling in mainland China, the lawyers added.
Pronouncing the verdict, the judge noted that Mr Chau's lawyer tried to prove that the defendant had not participated in the side-betting activities but she concluded such operations would not have been possible without his approval.
The court has ordered the gambling mogul and his co-defendants to pay the government £678m and financially compensate various casino operators.
The junket industry has collapsed in Macau since Mr Chau’s arrest after the operator shut its VIP rooms.
In January 2022, the city police arrested Levo Chan, a former boss of another leading junket business, for allegedly running illegal gambling operations.