HMAS Cerberus, a navy training base in south-east Melbourne, has returned to normal after a routine inspection of the barracks raised the alarm early on Thursday afternoon and police and the bomb squad were called to investigate.
A 400-metre exclusion zone was set up around the facility on the Mornington Peninsula and the base went into lockdown.
Superintendent Neil Paterson from Victoria Police said the materials found are hazardous and not normally found in barracks.
He dismissed any suggestion of terrorism and said there was no immediate threat.
A 30-year-old able seaman was taken in for questioning by police but has since been released.
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