A massive sperm whale which washed up near a popular Nelson beach may be left to rot because it is too big to move.
The 18.2-metre behemoth weighs maybe more than 50 tonnes and two large diggers were unable to move and bury it near the Blind Channel end of Rabbit Island, says the Department of Conservation's Chris Golding.
They are now trying to decide how best to dispose of it.
"One option being considered is to leave the whale tethered where it is to decompose naturally in the tide," Mr Golding said in a statement.
"This was done with three sperm whales that stranded in Golden Bay in November 2014. The whales were tethered off Farewell Spit and decomposed to bones within four weeks."
The whale was in an area not frequently used, about 4km from Rabbit Island's main beach and picnic ground, he said.
Local iwi have blessed the whale and removed its jawbone and teeth.
Meanwhile, the department is warning people wanting to look at the whale not to touch the decomposing carcass and that removing body parts is an offence.
It is not clear why the whale stranded. It was seen swimming in Tasman Bay last week but found on Rabbit Island on Friday, Fairfax reports.