A former security chief for FIFA was speaking at a forum on match-fixing organised in Singapore.
"Malaysia is the epicentre of trade for Southeast Asia," said Chris Eaton, an independent industry consultant and FIFA's former security chief.
He said Singapore had managed to break up some football match-fixing syndicates, although he added some remained working in "close association" with syndicates in Malaysia.
Eaton was speaking at a forum on match-fixing organised by the Global Lottery Monitoring System (GLMS) in Singapore.
The GLMS was set up last year by 27 lottery operators to monitor match-fixing around the world.
Singapore has cracked down on football match-fixing, leading to the arrest in 2013 of Singaporean businessman Dan Tan.
Former Interpol chief Ronald Noble described the Singapore-based ring that Tan allegedly led as the world's "largest and most aggressive match-fixing syndicate, with tentacles reaching every continent".
Christian Kalb, director of Paris-based gaming consulting firm CK Consulting who also spoke at Monday's forum, said illegal betting worldwide is believed to be worth up to 500 billion euros ($553 billion).