MELBOURNE, Sept 21 (Reuters) - Australia's Federal Court backed a challenge on Wednesday by a Tiwi Island traditional owner against a drilling permit for Santos Ltd's Barossa gas project, the Environmental Defenders' Office said.

"Tiwi traditional owner Dennis Tipakalippa has won his landmark case over Santos' approvals to drill precious Tiwi sea country," the office, which handled the case for the indigenous landowner, said on social media.

"The Federal Court of Australia has found that Santos failed to consult traditional owners as required," it added.

Santos had no immediate comment. (Reporting by Sonali Paul; Editing by Clarence Fernandez)