"On behalf of Athletics Australia, I extend our deepest condolences to Jarrod's family and friends and urge the athletics fraternity to support each other at this difficult time," Gocher said in a statement.
Bannister won javelin gold at the 2010 Commonwealth Games and finished sixth in the final at the 2008 Olympic Games. His personal best of 89.02 metres, set in Brisbane in 2008, remains the Australian record.
Former Olympian and renowned athletics commentator David Culbert described Bannister on Twitter as "a super athlete who sadly had many demons".
Bannister's last major competition came at the 2011 world championships in South Korea where he finished seventh in the javelin final.
Two years later, Bannister was banned for 20 months for failing three whereabouts drug tests.
- AAP