NSW Sugar Milling Co-operative boss Chris Connors said it was amazing refining operations constructed to process Australian raw sugar were being serviced by overseas supply.
"Our forefathers would be rolling into their graves," he said after the first public hearing of the Senate inquiry into sugar marketing, held in Murwillumbah last week.
"A lot of this sugar is coming from companies that have subsidies or protection in place for their own sugar - it makes a mockery of free trade agreements being spruiked."
Mr Connors (pictured) said the federal government needed to act to ensure Australian grower-owned businesses were not destroyed.
"The impacts of major foreign owners in the Australian sugar industry has left growers, and some millers and refiners, exposed to unfair practices," he said.
"There is little real protection under the Commonwealth Competition and Consumer Laws.
"Certainly there is no protection for the growers."