A large shark came within metres of swimmers at Papamoa in the Bay of Plenty today.
Lifeguard Shaun Smith said the two-metre bronze whaler was patrolling a 2km stretch of shallow water near the surf club.
Swimmers were kept out of the water for half an hour until the shark swam away.
Lifeguards are keeping an eye out for it and will clear the beach if it returned.
Export lamb roasts which spilled from containers from the grounded cargo ship Rena have been blamed for bringing more sharks than usual into the shallows off Tauranga.
"I would think if you got a chance to eat some nice export lamb you'd be pretty keen wouldn't you? ... If you were a shark I think they'd be right up your alley,'' Mr Smith said.