The man reportedly sped into waters off Burleigh Heads on Tuesday morning, taking off his shirt and donning fins before diving into the water to cut the baby free.

It’s unknown how long the baby had been trapped.

The man is being hailed “a hero” on social media, however he risks a fine for interfering with shark control nets.

The government has established a 20-metre exclusion zone around shark control equipment.

Failure to adhere to that distance could attract a $522 fine.

Rescuers from Sea World were preparing to deploy a team to free the trapped mammal.

-AAP/Christine Flatley