The functions were limited given the island was uninhabited, undeveloped and privately owned.
The department's responsibility was "to support the minister in exercising her functions".
Minister Mahuta, expressing her condolences to those affected by the eruption tragedy, said while she had responsibilities for offshore islands that aren't part of a local council, like Whakaari/White Island, they did not extend to any responsibility on access, tourism permits or health and safety.
"It is a private island and active volcano with no district plan under the RMA. Such decisions are made by the owner who gives permission to tourism operators to access the island.
"I do not have consenting or permitting responsibilities for the activities of tourism operators and I do not have health and safety responsibilities for the operations of private businesses, such as tour operators. This is the responsibility of local operators who carry out activities on the island. They are registered by WorkSafe NZ."
A spokesman for Mahuta's office said her responsibilities for offshore islands such as Whakaari/White Island "relate to planning such as the development on nearby Motiti".
But because Whakaari was a private scenic reserve, she had no role.
Internal Affairs said it had no role in the licensing of adventure tourism operations or in compliance with those requirements.
It confirmed the Whakatane District Council had no responsibility for the island.
The department had a memorandum of understanding with the Bay of Plenty Regional Civil Defence group to exercise the minister's roles in an emergency response. That response was activated after the fatal eruption on Monday.
The Bay of Plenty Regional Council said it had no legislative responsibilities for Whakaari/White Island.