Liquefaction from the Christchurch earthquakes may have unearthed four taonga on the banks of the Heathcote River.
Two pounamu toki, a sandstone file and a wood carving, were found last October by a member of the public and the Canterbury Museum is now looking after them.
Ministry of Culture and Heritage senior adviser Liz Cotton says the items were first passed to Ngai Tahu who delivered them to the museum.
Ms Cotton says by law, her ministry is obliged to return taonga to iwi, although it has not yet received any ownership claims.
The ministry will assess any claims and make a recommendation to the Maori Land Court for a judge to decide ownership.
The Historic Places Trust may initiate an archaeological dig where the taonga were found, she says.