She said marks on the bone and tyre tracks leading to the carcass show it was likely removed by humans.
Removing whalebones from a beachcast animal is an offence under the Marine Mammals Protection Act of 1978, and offenders could face fines up to $250,000.
Cole said whalebone was a highly prized taonga for iwi and used in carving.
She said it was disappointing someone had stolen it before the appropriate protocols and tikanga had been observed.
Ōraka Aparima kaumātua and kai rongoā Muriel Johnstone said the rūnaka were extremely upset the whale was not offered its due respect in terms of tikanga.
“We know and treat whales as rangatira [chiefs] of the sea and as such deserve appropriate protocols said over them,” Johnstone said.
“This includes a farewell address and appropriate karakia. This then allows us to treat the whale as a gift from the sea and use its resources. These include the bone, teeth and oils that we use as did our ancestors.”
She said it was obvious that someone knows the value of the taonga and had deliberately removed and stolen the jaw.
A similar instance took place in 2015 when the jaw was removed from another sperm whale that had also washed ashore at Oreti Beach.
Anyone with any information on the missing whalebone is asked to contact DoC on 0800 DOC HOT.
