Senior Constable Brett Otto at the scene said the pipe bomb would "need to be ignited to go off".
He said it was not a high-risk area for someone to set off a bomb and there was no evidence of anything other devices being let off in the area.
"They are probably just being silly and ... trying to make a loud noise. Just kids mucking around and playing silly buggers."
Otto said beachgoers, many of whom were going about their business on the beach when NZME arrived, had been curious about what was going on.
"We are just making sure it's safe, that's why we have got the bomb squad coming."
A police media spokeswoman later said the pipe bomb had been disposed of without incident and inquiries into how it came to be there were ongoing.