A Sunshine Coast man accused of being the mastermind of the world's largest online spam operation, which could send 10 billion emails a day, faced court in Brisbane today.

Lance Thomas Atkinson, 26, has admitted to being behind a large-scale spam-sending operation that sent emails to internet users all over the world.

Those emails encouraged people to click through to websites that allegedly used false claims to peddle prescription drugs, as well as "male enhancement" and weight-loss pills.

Atkinson, who had already been fined $16 million by US authorities over his spam set-up, this morning faced court action from the Australian Communications and Media Authority.