It is unclear how long the head of Tasmania's prison system will be on leave.
Barry Greenberry was recruited from Britain for the top job last year, after a damning independent prisons report which found inmates were being warehoused instead of rehabilitated.
Last month, the Justice Department confirmed Mr Greenberry was on leave after just seven months in the job but gave no explanation.
Prisons Minister Nick McKim still will not elaborate.
"Individual employment matters for individual employees are not matters for Ministers to get involved in, or to offer a commentary on, so you'll need to address those questions to the department," he said.
The Justice Department says it does not comment on the personal circumstances of employees.