Betting Risk Analyst With the gambling industry turning over more than a trillion dollars a year, organised crime networks are exploiting vulnerable sports like tennis, to fix matches and launder money.

"There are literally dozens of tournaments which are taking place every week and the gambling markets will take bets on any and all of those levels of tennis, so the possibility for corruption is extensivereturns Monday with this must watch episode, three months in the making, with new revelations and exclusive interviews.

BAD SPORT, reported by Linton Besser and presented by Sarah Ferguson, goes to air on Monday 1st February at 8.30pm.

It is replayed on Tuesday at 10.00am and Wednesday at 11pm.

It can also be seen on ABC News 24 on Saturday at 8.00pm EDT, on ABC iview and at .

I'm Sarah Ferguson and I'm looking forward to a cracking year.

For the past two weeks, sports fans in Australia and around the world have been riveted by the corruption scandal that's plunged the game of tennis into crisis.

Since the story broke on day one of the Australian Open, with allegations that match fixing is rife, tennis authorities have been in damage control: at first denying there's a systemic problem and then, mid-last week, ordering a review of the claims.

For the past three months Four Corners has been investigation corruption and match fixing in sport.

Our investigations confirm the problem in tennis has been systemic for over a decade and, until last week, largely ignored by tennis authorities. Four Corners has uncovered an explosion in online gambling markets, where match fixing can flourish, including operations linked to organised crime worth billions of dollars.

Tonight, reporter Linton Besser takes you inside the murky world of the offshore bookmakers and criminal operators preying on the games we love.

This small club in suburban Adelaide is hosting a men's professional tennis tournament - and they're running it from a shipping container.

Players stretch on the oval next door and their VIP lounge is the local cricket club.

JAY SALTER, FORMER TENNIS PLAYER AND COACH: You literally go from one week to the next, um, just trying to pay those bills or pay for the hotel room or sleep in a hotel room with five other guys or whatever you can do.

LINTON BESSER: There's very little prize money here.